
Twenty years ago, very few scientists even knew about something called the gut microbiome. Now, with over 70,000 research papers published on the subject, this complex ecosystem, home to trillions of microorganisms, is recognised as a key factor in our physical and mental wellbeing.
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We have as many microbial cells as we have human cells. That is why they have such an impact on our health. We can't change our genes, but we can influence and change our gut microbiome.
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Hey, guys, how you doing? Hope you're having a good week so far. My name is Dr. Rangan Chatterjee and this is my podcast, Feel Better. 20 years ago, very few scientists even knew about something called the gut microbiome. Today, with over 70,000 research papers, this complex ecosystem, home to trillions of microorganisms, is recognized as a key factor in our physical and mental well being. Today's guest is Dr. Emily Leeming, microbiome scientist and researcher at King's College London, registered dietitian, former chef and author of the book Genius Gut the life Changing science of eating for your second brain. In our conversation, Emily explains how our understanding of gut health has evolved dramatically over the past two decades to the point where we now know it plays a crucial role in everything from our immune system, our ability to respond to stress, our skin, and even our mental well being. But how can we assess the state of our own gut health? Well, Emily shares how observing your own bowel movements can often tell you more about your gut health than costly microbiome tests. And why some bloating after meals may actually be a sign of a healthy gut. We also discuss how our gut health has been negatively impacted by our modern lifestyles. Stress, sleep quality, our modern diets, as well as the timing of our meals. And Emily shares why time restricted eating and earlier dinner times can be really beneficial. She also gives some practical advice about what we can eat to improve the state of our gut health and explains why breakfast offers us a golden opportunity to support it. And and why she is not a fan of recommending that everyone eat 30 different plant foods each week. Emily is someone who is highly knowledgeable and passionate about helping us all improve the health of our guts. Her message is clear. Nurturing our gut microbiome is not about following rigid rules. It's about understanding this remarkable ecosystem and working with it and not against it. I thought we'd start off by really diving into the current state of gut microbiome research. As you write in your new book, 20 Years Ago, we didn't really know what the gut microbiome was. I would say in the last five or 10 years, it's become one of the hottest terms or trends in wellness. Could you take us on a bit of a journey? What did we know 20 years ago and what do we know today?
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Yeah, it's been a real roller coaster, hasn't it? Yeah, and I think it's a trend. We talk about it being a trend, but it's a trend that's here to stay. So really, 20 years ago, most of us, including many scientists, didn't even know that the gut microbiome existed. Now, 20 years later, we've had this evolution, this tsunami of research papers coming out. A lot of that is due to the fact that we've had the technology to be able to understand not only who's there. So with these tiny living organisms that live in our gut, but also now, what are they doing and how are they impacting our health? So, for example, go back 20 years, maybe a handful of papers out on the gut microbiome. In the last year, we've had a phenomenal amount of research that's really understanding and underpinning the fact that this gut microbiome is seen as a forgotten organ. It's not just helping with our digestion, it's influencing the rest of our body and very much having a really big impact on our health. But in a way that's really useful for us to be able to understand, because we can't change our genes, but we can influence and change our gut microbiome, giving us another tool to influence our health.
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The term gut microbiome. Not everyone is going to understand what that means. How do you explain to your patients what it is?
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So I really talk about it in really simplistic terms. We don't need to get in the weeds about it. Effectively, you've got 100 trillion microorganisms. So these are tiny living organisms that live in your gut. They are made of bacteria, viruses, yeast, fungi. You've got a whole collection of different communities in there. These communities are not just helping with your digestion by breaking down food, but they're also producing special molecules that can travel across your body. They can cross your gut barrier lining into your body, cross through your bloodstream to different organs, and influencing your health. So this is a live ecosystem that's living in your gut that is directly responding to you, and you're responding back to it.
B
Now, the interesting thing for me about gut health, for want of a better term, is that it sits at the heart, or it seemingly sits at the heart of multiple different states in the body, multiple different diseases. So, as a medical doctor, I've always been fascinated by root causes. Okay, so let's say inflammation, for example. We know that chronic unresolved inflammation underpins, in some way, at least many of the chronic Diseases that we see, whether it be some cases of depression, heart disease, autoimmune illness, you know, dementia, although seemingly separate diseases. When you go back up the chain and look at root causes, we see that chronic unresolved inflammation is one of those root cause drivers. Yes, I know inflammation and gut health are strongly linked, but I think we can look at gut health in a similar way. Right. That it actually lies at the heart of multiple different conditions.
A
Absolutely. I mean, it's really considered to be, you know, this new cornerstone of health. And I think when we, you know, talk about the fact that we've got these kind of tiny, you know, organisms invisible to the naked eye, you know, how can they be really that impactful for our health? I get asked that, you know, quite often and I kind of laugh and I say, yes, it does seem quite fantastical. But I think we've got to think about looking at it from an evolutionary perspective. So actually, if we go back in time, before humans even existed on this planet, this world was dominated and owned by microbes. Microbes are on every single living surface. They continue to be today. And effectively we've then co evolved with these microbes to the point that we have as many microbial cells as we have human cells. So just showing that throughout evolution, we have then relied on them and they've relied on us. And therefore that is why they have such an influential effect on our health and not just helping with our digestion and therefore influencing all these different disease states, but also things in health as well, like your energy, your mood and your cognition. So really having a key play in that aspect, many different aspects of your health.
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How might any one of us know if we have excellent gut health or poor gut health?
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So most people might think, oh, I need to go and have a gut health test. But actually what a gut health test is going to tell you is just what microbes that you have and perhaps how diverse those microbes are. So we talk about a healthy gut microbiome as one that contains a range of different types of microbes, similar to a company that has lots of different jobs. You don't just want a company with a marketing department. You also need HR and you need product developers and you need a PR team and probably someone to organize some work drinks for some fun. Your gut microbiome needs all these different kind of jobs as well. But the thing is, a gut microbiome test is incredibly expensive and isn't going to tell you much more than that. It's not going to give you any actionable Advice. So actually, the real thing that you can do, which is completely simple, easy, affordable, free, it's just look in the toilet bowl and look at your poo. I talk about poo a lot because really, it's such a great sign of telling you how healthy your gut is and how healthy your gut microbiome is, because a significant portion of your poo is made up of the bacteria that's kind of dead, some still living, that is coming from your gut microbiome. So what are the key things we want to be looking for? We want to make sure that you're going between three times a day to three times a week. That's quite a broad range. But anywhere within there that's normal for you. You want it to look like a smooth sausage or a sausage with cracks in it.
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Okay.
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And also have it to be a kind of brown, dark brown colour. Red flags would be things like having blood in the stool, whether that's coming up as being black or kind of red. That's something where you might want to go and get that checked out and just see if there might be something else going on with your doctor.
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So this is really interesting. Okay, so you're saying that basically a lot of these gut health tests that exist today, these commercial tests, probably aren't gonna tell you that much. The best way that we can all do is look at our stool, basically. And you're saying that there's a range. Now, what was interesting about that range is that it's huge, right? Three times a week. You know, opening your bowels to three times a day is a huge range, isn't it? Do you think sometimes people feel, well, I'm only going three times a week, that must mean I'm constipated. Whereas you're saying certainly from that that that could be just your normal.
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Yeah, I think we really think about what is your usual. If you're within that range, if you have a change from your usual, that could be the sign of a problem. So even if perhaps you're within that healthy RA and you're going more often, and then you suddenly start going much less, that could also be a sign that perhaps there's not something going on that's quite so healthy. And I think also when we're talking about the health of your gut microbiome, it's not just about the health of your kind of gut, and which is a really, you know, your poo is a really great sign of being able to see how healthy your gut is. It's also how you feel. And I think we've really got to recognize that health is every single day of your life. It's not just about, you know, trying to ward away some kind of future illness. Of course, that's still really important. But I really want to kind of bring back this conversation to health, being about how you feel right now. It's your energy, it's your mood, it's your cognition, and those pieces of the puzzle every single day is then making up that picture of your health throughout your life.
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Yeah, I love that. Absolutely love that, Emily. And I think it's a really great point. Let's go back to that range of bowel opening, because I. If. Let's say you're only going three times a week, and yes, that may be in the normal range, but if at the same time you're feeling uncomfortable, you feel like you need to go, but you can't go, then even though that's technically in the normal range, it's probably not ideal for you.
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Absolutely.
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Do you know what I mean? It's like it's trying to bring those two things together. Yes. Use a scientific table, for example, to help guide you, but then correlate that with how you feel. You know, what's your bloating like, perhaps what's, you know, how do you. Do you feel light? Do you feel heavy? Do you feel full? Those things are really important as well, aren't they?
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Yeah, completely. And I think we've got to think about, you know, how easy is it for you to go to the bathroom? Is it causing any pain? Is it causing discomfort? Those are also things that, you know, we want to kind of maybe perhaps explore further.
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People often don't want to talk about this, I guess, but it's so important, isn't it? How easy, in your view, should it be to. For someone to open their bowels when they go to the toilet?
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It should be really easy. It shouldn't take that long. It should be something that, you know, you don't have to push strain. It shouldn't be causing any pain. It should just be something that just feels very intuitive. It's happening, and you feel that everything is then completely out at the end as well.
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So that's what it should be. In your experience, how many people or what percentage of the population are able to open their bowels like that?
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So I think it's quite surprising how many people are classified as having constipation. So I think that's about ranging anywhere between 20 to 40% in the statistics. But actually, if we think about it that everybody at some period of their life will have symptoms of constipation and perhaps maybe not be completely constipated in terms of not going that often, but still struggling with some aspects of going to the bathroom. And I think we really need to be talking about this. We've got such a taboo around talking, talking about. Like, I very much feel very strongly that we should say the word poo, because that's the word that we use. And I don't want to go around saying the word stool or, you know, bowel movement or, you know, let's just follow what it is.
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Let's go with the word poo. Okay. Right. So it's interesting. I completely agree with you. I think we need to talk about this more. Okay. Because if we don't, we're not gonna know what is normal. We're not gonna stop paying attention to what is that. I mean, on another note, this whole thing of paying attention, it's quite striking these days for me that many people cannot actually go to the toilet anymore to have a poo without their phone. Okay. Which is really interesting. I'm not necessarily judging that or criticizing that. I'm just saying it's interesting because if you're trying to pay attention to how certain things feel with your health, if you're distracted whilst you're engaging in those things, whether it's anything, you know, it's not just going to the toilet, then you may not be picking up on the signals. Right.
A
I think it's such an important point that we need to be, you know, paying attention to what those feelings are, those urges, and really respecting those urges. So if people who are struggling with going to the bathroom and doing a poo, you know, it's really being in tune with those urges, don't ignore them. Cause that can make matters worse. Another really great tip is actually making sure that your kind of knees are with kind of a propped up on a. What we can call a poo stool. Right? Yeah. That just helps to straighten up your kind of back end to make that poo come out much easier. In terms of food, there's actually some really great evidence around having two kiwis a day. And that's because it's so rich in fibre, particular type of fibre, that really helps to kind of smooth things through. So you've got a smooth exit into the toilet bowl. And there's a few. There's many other things that you can do. Most of the issues that we have with being problems with poo and constipation diarrhea can be solved with easy, simple diet and lifestyle changes. And then of course, if you're having issues, please do go explore that with your doctor and your gp.
B
Well, we're going to get into all the practical things shortly in this conversation, so let's go into what a lot of your research has been. All the research you put in Genius Gut, your new book. Right, let's talk about that. And I guess, you know, we're talking about gut health and we're going to talk about how many different things affect our gut health, not just our diet. One of the reasons I think many people struggle to go to the toilet these days is because of chronic stress. So can you talk about the relationship between chronic stress and our gut microbiome and perhaps our ability to have a poo?
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Yeah, absolutely. So stress is something that, you know, for many of us it's just part of life, right? We're all gonna come across something that's stressful. Little bit of stress, absolutely fine. It's healthy for you, it's what makes you perform well on exams. And then your body goes back down and recalibrates back to normal when we're getting. And so for some people that can cause just that small amount of stress, that spike can cause them issues. I'm sure everybody knows someone or maybe experiences themselves, they need to run to the bathroom, they've got perhaps diarrhea or they can be constipated, it can be either way. That can also happen with chronic stress. So stress that is just consistent high levels of stress that is then impacting how their digestion is working. The reason that's happening is because our body goes into what we call fight or flight mode. And that is where, you know, going back to kind of caveman days, we are needing to shut down the processes in our body that aren't essential. If we need to run away from a tiger and save our bacon effectively, we need to put all that energy into our muscles. We need to be running away. And therefore our digestive system doesn't get as much blood flow as it perhaps normally would. There's also this very powerful connection between your gut and your brain, so much so that we call your gut your second brain because they're physically connected through a long wandering nerve called your vagus nerve. Now, this vagus nerve acts like a two way pathway between your gut and your brain. And we think we know that your brain is effectively the CEO of your body, but your gut is very, very chatty too. And actually 90% of that chat between your gut and your brain is coming from the gut.
B
Now, that's interesting, right? So you're saying there's this gut brain highway. It goes both ways, but it's not going both ways equally. 90% is going from your gut to your brain. Therefore, we can conclude only 10% is coming from your brain back down to your gut.
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I mean, so much communication is happening. You know, you've got your brain as the CEO. It's managing what's. What's going on, but it also needs to have constant feedback coming back to its kind of central authority. But your gut, therefore, is then incredibly reactive to when things like happening with stress, and we see this with your gut microbiome as well, that your gut microbes, if you've got a healthy gut microbiome, are able to actually help you manage some of your stress levels. The thing is what happens is that it acts a little bit like an elastic band, that if it's stretched too often, for example, if you're getting stressed consistently again and again and again, that relationship can actually end up going the other way and becoming problematic because those molecules they're producing ends up being kind of actually exacerbating perhaps your stress response. And this is kind of early emerging science that we're seeing this kind of modeled in mice and then seeing this kind of in human studies where we see kind of links happening between people being more stressed and having a kind of less diverse and less healthy gut microbiome. And we see in mice, for example, that two weeks of constant stress is enough for them to have a significantly different gut microbiome.
B
Wow. I think people intuitively, if they think about it, understand that there's a gut brain connection, that physiology and psychology are intimately related. You cannot separate the two. What's interesting for me, though, is how much of this communication back from our gut to the brain is mediated through our gut microbiome. Because some of it, I guess, is just through the vagus nerve, but I guess some of it will be from the metabolites made by the gut microbiome, which then go via the vagus nerve as well to the brain. Is that how it works?
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Yeah. So there's multiple different ways that your gut microbiome is talking to your brain and influencing your brain. Again, this is really exciting kind of early research that we've only really started to kind of tap into in the last couple of years. What we're seeing is that, yes, we've got this communication, the most direct communication is through the vagus nerve. That's we think about that, that's like picking up the telephone to have a direct call. And then we've got the molecules, those metabolites that are produced by your gut microbes. They can also influence your brain. A great example of those are short chain fatty acids that your gut microbes can. Only your gut microbes can make these short chain fatty acids. Your body is not able to make it themselves. They make them by feeding on fibre from the food you eat. And these short chain fatty acids have an anti inflammatory effect, but they're also really important for your blood brain barrier. This is a protective fortress around your brain that effectively has gateways in it that stop anything that's problematic, like toxins or kind of harmful molecules from getting in. But it also needs to be stay strong and healthy to let in those nutrients that your brain needs. So that's an example of metabolites. Your microbes are also in tune with your immune system and signaling to your brain through immune cells as well. So that might be changing shape and different formats, but perhaps like sending a letter in the post, where you give it to the postman and then it maybe goes to a few different sorting offices and then ends up at your door. That is also another pathway that your gut microbes are signaling to your brain. And then last but not least, we see this relationship with neurotransmitters and your gut microbes. Early signs that they're helping to supply your brain with the building blocks that your brain needs to make things like serotonin, your happy hormone, and also dopamine, which is your kind of, ooh, I like it. Do it again. Neurotransmitter.
B
Okay, this is fascinating. So let me try and summarize it the way I heard it and you can tell me if I've got this right or not. Okay, so we've got this gut brain access. There's a communication from our gut to our brain and back from our brain to our gut. 90% of that communication is going from our gut to our brain. But it's not just one thing. We can think about it as maybe from what you said, and of course the research is early, we'll learn more in the coming years. But let's say there are four different motorways going to the brain. One of those motorways is via the vagus nerve. We're getting messages from the guts of the brain. Another one of those motorways is through the microbiome. The gut bugs are eating the fiber. Let's say that we're eating, making short chain fatty Acids like butyrates. So the butyrate is taking a different motorway to get to the brain to have anti inflammatory effects. You're also saying that it can be via the immune system. So the gut bugs interplay with the immune system and those signals get sent by Highway Number 3 up to the brain. And if I recall it right, highway number, not highway. I've been in America for two weeks. That's why I'm saying highway motorway number four might be that the gut itself directly is making neurotransmitters like serotonin or something like dopamine. And those are taking perhaps a different motorway to get to the brain. Is that roughly accurate to what you just said?
A
Yeah, so roughly accurate. Obviously this is incredibly complex and I think we're breaking it down to those four pathways. Absolutely.
B
And there could be a hundred pathways.
A
Yeah, it could be a hundred. There's two. So many different things going on.
B
But the basic principle.
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The basic principle, Absolutely, absolutely. It's, you know, you've got the neurotransmitters, immune system metabolites, those molecules and you've got that direct pathway which is the vagus nerve. I think the really interesting one, which I find is talking about this piece around the neurotransmitters. So I don't know whether you've seen this, it's all over Instagram. I see that's anything related to this topic. It's kind of, you know, 90% of your serotonin is made in the gut. And I was slightly kind of like grit my teeth a bit at that because in a way it is true. But the insinuation there is that serotonin is actually influencing your brain. Let me just unpick why that isn't actually quite the truth.
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Okay, great.
A
So, yeah, so serotonin is, you know, we talk about very simplistically as being our kind of happy neurotransmitter that is used in our brain. But serotonin is also like many other molecules in our body, used for many other different things. That's not just kind of mood related. So your gut microbiome and your gut make serotonin? Yes, 90% of serotonin in your gut. The thing is that serotonin is too large a molecule to fit through that blood brain barrier, so it cannot pass into the brain to influence your mood. The role it's playing is it's actually helping with your digestion, it's helping your body to the muscles to move, to move the food kind of through your gut. Playing still a really important role. So what your microbes are actually doing is helping to supply and manage what the building blocks of that serotonin is. So tryptophan, which is an amino acid, is used to convert into serotonin. It's a building block that's made into serotonin, but it needs to be supplied to your brain first because it's a smaller molecule. So it can fit through that door, that gateway from your blood brain barrier, and then your brain can make serotonin in the brain that's gonna influence your mood. So we think that is the relationship.
B
Yeah, thank you for clearing that up. So can we say therefore still though, that although the serotonin made in the gut may not actually be the serotonin that gets into the brain, can we still say that actually feeding your gut in the right way, improving the health of your gut microbiome can have an impact on the serotonin that is made in the brain, but it happens through the mechanism of tryptophan, let's say.
A
So I think that's the most logical what we know from the research so far. I think we've, again, this is obviously early science, but I think that is really the direction that we're seeing this relationship going in. And I think this really gives us this kind of actionable viewpoint where, okay, can I change my gut microbiome? Can I help to supply, you know, these extra amino acids to the brain so that that can then potentially have an influence on the mood? And again, you know, this is very much in the viewpoint that this is an extra tool on the toolkit. This is not to replace conventional approaches to kind of mood management, but I think really can be something that we can, you know, be very excited to explore. I think in the next five years, you know, really looking at, you know, probiotic strategies, for example, for stress, for mood, how can we make things really easy for people to make changes to their diet so that they can feel happier, you know, sharper mood mentality, that's what we all looking for in life.
B
If we go back 25 years, right, and we're saying that back then this field of gut microbiome research was very, very early, barely starting right back then, I guess we probably still knew that certain things are important, right, for our well being. You know, a good minimally processed food diet is important. Moving your body regularly is important. Trying to get a decent amount of sleep, whatever that is for you, is probably quite important. Making sure you're not chronically getting stress. I don't think we were as stressed as a society back then is important. Just to play devil's advocate for a moment, Although gut microbiome research has been phenomenal, I've been fascinated by it because I've written about it as well, like you. Right. So it's incredibly interesting in terms of practical take homes. And I know you've got your own practical take homes, which we're going to talk about. Could we almost make the case in some ways that it's just reminding us or giving us even more evidence that what we kind of knew 25, 30 years ago holds true? And it holds true for many reasons, including because those things have a positive impact on the gut microbiome.
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Absolutely. I think it's such a good affirmation of that. It's the real foundational things that are impactful for our health. And I think one of the things that I love to say about the gut microbiome, I'm like, if you can't do it for yourself, do it for your gut microbes. You know, think about it like it's this Tamagotchi that you need to look after. You know, use that as a way that, okay, I do need to do this because I need to look after my gut microbes and, you know, I'm then going to feel better as a consequence. And I think as Brits, we're kind of weirdly bad about looking after ourselves and very good at looking after other people. And perhaps we can kind of bring that into play for ourselves, too.
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I agree. I think Brits are probably not fantastic at that. In my experience as a doctor, I would say I've seen a lot of women in that category, probably more than men, and that's biased by the patients I've seen. So that's not an unbiased random sample. It's people who I saw coming into my practice. Right. But I very much saw a lot of women who would put everyone else's needs before their own. You've got an interesting section in your book about the difference between female microbiomes and male microbiomes, so perhaps now's a good time to talk about that. What is the difference? And also within female microbiomes, I'm assuming it can also change throughout the menstrual cycle. Just taking a quick break to give a shout out to AG1, one of the sponsors of today's show. Now, if you're looking for something at this time of year to kickstart your health, I'd highly recommend that you consider AG1. AG1 has been in my own life for over five years now. It's a science driven daily health drink with over 70 essential nutrients to support your overall health. It contains vitamin C and zinc which helps support a healthy immune system, something that is really important, especially at this time of year. It also contains prebiotics and digestive enzymes that help support your gut health. All of this goodness comes in one convenient daily serving that makes it really easy to fit into your life no matter how busy you feel. It's also really, really tasty. The scientific team behind AG1 includes experts from a broad range of fields including longevity, preventive medicine, genetics and biochemistry. I talk to them regularly and I'm really impressed with their commitment to making a top quality product. Until the end of January AG1 are giving a limited time offer. Usually they offer my listeners a one year supply of vitamin D and K2 and five free travel packs with their first order. But until the end of January they are doubling the five free travel packs to 10 and these packs are perfect for keeping in your backpack, office or car. If you want to take advantage of this limited time offer, all you have to do is go to drinkag1.com livemore that's drinkag1.com livemore this episode is sponsored by Thriver, the app that helps you listen to your blood and get personalized guidance on how to optimize your health and fitness. Now I think regular blood tests can be a really valuable tool that can help tell us which lifestyle changes are working and where we might want to make changes. And Thriver is the perfect tool to help us do that. You just take a blood test at home, which is really easy. I do it regularly. Just a simple device you stick on your arm that draws blood automatically. Easy, quick, pain free, even if you're not great with needles. And then you just send it off and get all of your results in a matter of days in an easy to understand app. And all of those results come with personalized lifestyle advice from doctors. You can then test again in a few months time and learn what's working well and where you might want to make some changes. For example, your average blood sugar, known as your HBA1C I think is a really important marker that gives you information on the state of your metabolic health and I personally like to check it every three to six months. The Thriver app is what I use to help me do this and it offers many different options, general non specific blood testing or you can get more focused on things like hormonal health, sports performance, nutrient levels and also with thriver you can test your APOB levels, a much more reliable indicator for your risk of heart disease than standard cholesterol tests. For listeners and my show Thriver are offering an exclusive offer of 20% off your first thriver cycle when you enter the promo code livemore at checkout. Just visit Thriver Co to get started today. That's T H R I V A co Thriver, listen to your blood.
A
So what we. So we see that children, when they're, you know, before they hit puberty, their microbiomes tend to be quite similar. And really we're then seeing this relationship at puberty, particularly with girls, there's a strong relationship with estrogen, the female sex hormone, and the gut microbiome. So it seems to be a two way relationship in the terms that your gut microbiome is helping to support your estrogen levels, but also estrogen levels also seem to be influencing your gut microbiome. With boys, we don't see this change so much at puberty, although there still is this relationship with testosterone. I get asked, does this mean that one's better than the other? We don't know that for sure. It just means that your gut microbiome is just kind of being more in tune to perhaps your different nutritional needs at that point and your different kind of hormonal needs and it's just kind of working in tune with you. With women, we then see that you get into adulthood and you've got then a slightly different microbiome to men. And we see this in diseases. What's quite interesting is that we'll see relationships between different types of microbes for men than we do for women. So I think really just highlighting how complex the gut microbiome is and just we need to be kind of careful about how we're talking about it. There's still so much that we need to uncover and still we don't necessarily know what quote, unquote, a healthy gut microbiome even looks like because it's so individual. And then we get into later life where for both men and women, that diversity of gut microbes starts to go down. And that just means that if there is, you know, infection, that your gut microbiome is perhaps less resilient to being able to kind of ward that off. With women, what's interesting when they go through menopause is actually we see this shift from their microbiome going back to being more similar to a men's microbiome.
B
Really?
A
Yeah. And we think again, this is probably because of this relationship with estrogen. What's fascinating about this relationship with estrogen? Again, this is very early insight, but it'll be amazing to see if we get more research in menopause, which we drastically need. But that it seems that your gut microbes are certain gut microbes are helping to support your estrogen levels because they're able to recycle some parts of waste estrogen. That estrogen is then taken back up into the body and could be made back into kind of new fully fledged estrogen again.
B
Wow. It's fascinating, isn't it?
A
I mean, there's so much more that we need to be kind of banging the drum for menopause. I'm thrilled that more menopause research is coming out. And we're, you know, it's 50% of the population, you know, we should know more about this. And how can we help women who are looking to resolve some of their menopausal symptoms? And again, the taboos and the kind of judgment that are put around, you know, all these things. I think we've got to think outside diet, outside lifestyle, really think about the environment we live in also influencing our health. And I mean that, you know, as kind of cultural norms and how we're made to feel about ourselves. You know, all those things are having impact on our stress levels, which is impacting everything.
B
Well, and as you talk about in your book, even those things and those messages and the way we interpret those messages could well be impacting our gut microbiome.
A
Yeah, absolutely.
B
Which is interesting.
A
Yeah. So we see that kind of older adults who are experiencing loneliness tend to have a less diverse gut microbiome. And this really starts to make sense where if we really recognize that everything is covered in microbes. I've got this cup of tea in front of me. There's microbes on this and the table. These aren't things that we need to be worried about or problematic. Many of them are harmless, friendly bacteria and other microbes. And so we're constantly introducing to our gut different new microbes. From one apple, we have 100 million microbes from just eating one apple alone. And we see that then in the gut. So this interaction with human beings is incredibly important. You know, if you kiss someone for 10 seconds, you can transfer 80 million bacteria to that's 10 second kiss. 10 second kiss.
B
What about 20 seconds?
A
22Nd? I mean, double the whammy. Double whammy.
B
I think some people will be quite excited to hear that. People may be a little bit freaked out to hear that, I think so.
A
What was interesting is that Some of the researchers who were looking at this said, is this, you know, could this be a new kind of dating technique? Because some of them, the metabolites that were produced by those bacteria could be then signaling back to us, depending on how enjoyable we find that kiss, that this is a kind of compatible mate or not. But again, it's, you know, if we think about the gut being the entirety of our digestive system. So the gut isn't just your stomach. The gut starts in your mouth and goes all the way down to the bottom. The microbes that you're introducing in your mouth are then quite often passing down through to your gut if they survive the acid pit of your stomach.
B
I love that. Because if we think about this in a much more broader philosophical level, the gut is in so many ways the interface between our external world and our internal world. Right. It's obviously where the immune system, well, most of the immune system is there in and around our gut. And so what you're saying about, you know, an apple or touching a table or loneliness or, I don't know, a 10 second kiss, right? Or you're dating, you kiss this person you're dating for the first time. Although it could sound quite wacky when you first hear it, the more you think about it, the more you go, well, wait a minute, it kind of makes sense, right? If you're gonna have this new partner in your life. And given how important mating is to evolution, it's not that surprising that there could be a link. Your gut microbiome, your guts could be doing some form of sensing here and going compatible, not compatible. Do you know what I mean?
A
Yeah, I think it kind of makes a kind of intuitive sense in a way. But I think again, we've got so much more to know in terms of the science. But this is what I think is so fascinating about this area. There's all these little kind of golden nuggets that are signaling that perhaps make complete sense to us. And we just need to then have a few more years to just really double down and explore this. But of course, the fact we go back to our microbes making up, you know, 50% of our cells, you know, they are heavily influencing, you know, pretty much every aspect of our body.
B
So they're not there by accident.
A
They're not there by accident. They're playing a role.
B
Yeah. Let's think about the things that we can do then to positively influence our microbiome with the knowledge that we don't yet know perfectly what a healthy microbiome is. There has been this maxim, this kind of truth, that we have thought for many years that a diverse microbiome is a healthy microbiome. Now, let's just examine that for a minute. Where has that come from? Do we know that to be true or are we still speculating?
A
So it's true in many ways, but it's also too simplistic. And I think many, many or most researchers in microbiome space kind of recognize this, that it's effectively the best measure that we have so far, but there are also problems with it. So it makes complete sense that we need to have a variety of different microbes. You know, again, like this kind of ecosystem, we need lots of microbes doing lots of different jobs. That also means that there's a resilience there because there's a community of lots of different types of microbes. So if a challenger comes in, you've got lots of different microbes that are going to be helped to kind of fight it off. The thing is, it is recognized as just being one metric. And also it might not be true of all situations that it's necessarily a healthy gut microbiome. I think a key example here is that we know in babies, for example, that a lower microbial diversity is actually more healthy than a high microbiome diversity. So there are different stages where we're thinking, actually there's a bit more to it, the other things that we really want to be thinking about, and actually there was a new paper out on this a few months ago of scientists grouping together and making a kind of consensus that we need to how can we understand and talk about a microbiome in a way that's really signaling many of the other different aspects that kind of make a healthy gut microbiome. So really thinking about, not just really who's there, it doesn't really matter necessarily what microbes you have, but what matters is what are they doing, what metabolites are they producing? These molecules are then having an influence on your health. And it doesn't matter, perhaps, that one microbe is called Ben and the other one's called Jill, as long as they're doing a role that is helping to support your health. That resilience piece is again, really important. Having a resilient microbiome.
B
What does that mean, a resilient microbiome?
A
So if a challenger comes in, so an infection or a kind of, you know, so that could be from a harmful bacteria, perhaps you've got a stomach bug from being on a holiday and you've come back and you're kind of feeling pretty rough. Your microbiome helps to kind of fight off that challenger that's coming in and that is a resilient microbiome. It's able to return back to its kind of normal, healthy self kind of rapidly and quickly.
B
And that sounds like a pretty reasonable thing to conclude, doesn't it, that that sort of principle stands true for many aspects of health. We want to be able to respond, we want to be able to deal with a stressor, an infection and then pretty soon after get back to where we were before. So it's really interesting because for many years I've also been talking about a diverse microbiome being important. And then over the last few years I always like to challenge myself in terms of my beliefs and where have they come from? And then I was trying to think, well, we say that a diverse microbiome is a healthy microbiome, but do we know that for certain? You know, I know there's some studies where they've looked at, I think is it the Hadza tribe and they've in Tanzania, a modern hunter gatherer tribe and compared them to an urban Italian population. I pretty sure that was it from a few years ago. And what it showed that we've maybe lost 50%, up to 50% of our diversity. I don't know if you remember the book Missing Microbes from Marty blazer, was it 10 years ago then, if you came across it, that was one of the first big books on the microbiome. I read when he was sort of making the case that could this increasing rate of chronic disease and autoimmune illness, could it all be linked with these missing microbes and are lower microbial diversity? But one thing I wanted to put to you, Emily, and it's really how my view on this has evolved. And you know, you're a very well respected microbiome researcher, so I'd love your view on this. It's like you said before, does that diverse microbiome be healthy hold true for everyone? Because there is a very common maxim now put out there that we should be aiming for 30 different plant foods a week. Where has this come from and why do you think it's been perhaps a little bit overrated? If that's a fair way of putting it, Absolutely.
A
I think that's it in a nutshell. So it comes from a study that came out in 2018 that was, it was called the American Gut Project and it was really a landmark study of its time. It got 10,000 people to send in Their kind of poo samples. And within that, they then did a number of questionnaires, and then they looked at lots of different things within this paper that they kind of produced. And one small aspect of this was looking at the relationship with the number of different plants that were eaten. One of my bugbears with this is that, you know, unlike many other nutritional research that happens, you know, it wasn't a really rigorously collected dietary data. It was effectively one simple survey question of people guesstimating how many plants they ate in a week. And then we come to the number 30. You know, why 30? Why 30 plants? You know, being associated with, you know, a high microbial diversity.
B
It divides by three, divides into 10, you know.
A
Yeah, they effectively, you know, they were like, okay, here's how many plants every. Everyone's going to be eaten. Let's split this into three groups, because what we do in research, we like to have nice three buckets that we kind of put people into. And so top bucket was people who ate 30 plants or more, and the bottom bucket of people who weren't doing particularly well were 10 plants or less. The average, obviously, were people in the middle. Take those out. And so they compared the 30 plants, the best people, to the people who were doing worse. Now that usually in science, if you're comparing people who are doing badly to the people who are doing well, you can have any number. It could be 25, it could be 40, it could be 15. And then within that, the way that the data was collected, it could actually be that perhaps are they just eating more plants in general and therefore are having a healthier diet? And could that relationship actually be from that? I do think, as a general advice, we do want to be having a variety of different plants in our diet because they're going to provide all those different nutrients and polyphenols and beneficial things for our health. But I really struggle with this, equating it to being the same as the eat a five a day message, which is based on thousands of different papers that have been reviewed by panels of experts to one single association within a larger study.
B
So you're basically saying, look, your view is that more plant foods and diversity in your diet is generally a good thing, but you're saying that we don't necessarily need to aim for 30, is that what you're saying?
A
Yeah, and I think, not getting hung up on, you know, I've definitely come across so many people who, you know, they have packed their fridge with so many different types of fruits and vegetables. They're incredibly stressed because they're noting down every single item they've eaten, you know, every meal. And then they think they can't eat a tomato on Wednesday because they had it on Monday. And then, you know, it's rotting in the back of their fridge. And I think really that's so counterintuitive and counterproductive to what it really is about, which is just really, again, as we said, those really foundational principles of can we get more fruits and vegetables in? You know, yes. Think about diversity and variety, but in a way that's like really simple and practical. Like perhaps it's picking up a bag of mixed fruits of the forest from the frozen berry section rather than just getting the strawberries or the raspberries. Perhaps it's getting those kind of ready packs of stir fried veggies. Cause you've got kind of maybe 10 different plants in there versus just picking out cabbage for your stir fry.
B
What about someone who says, well Emily, I hear what you're saying, but I find the 30 plant foods a week quite helpful because it gives me a target and it helps inspire stroke, encourage me to keep looking at different ways that I can keep adding these things in. What would you say to that person?
A
I say, and as I say in my book, I say if that's you, that's great. But as long as it's in the way that you find healthy and easy and, and you recognize that it's not the be all and end all and.
B
It'S not the be all and end all for everyone.
A
It's not the be all for end all for everyone. And I think, you know, it's finding something that works for you. And I think more often than not I find that it's the other way where people are then incredibly stressed about it, think it's literally, you know, the only way you can get good gut health and it becomes just this, its own beast and it's just not.
B
Yeah, I really appreciate that. So my experience with this has been, and one of the reasons why I am evolving my view on this is based upon what I've seen with patients. I'll give you an example. And in my new book that's just come out, I put this case study in chapter one. So this lady had heard that advice online that I need 30 different plant foods a week to have a good healthy gut microbiome. And so I hadn't seen her at this point. She was just very health conscious middle aged lady, right. And so she was trying her best. She was reading all the Blogs, listening to the podcasts, she was going to the shops, trying to do it. She didn't feel good, right? Every time she increased it, she was getting bloating, she was getting constipated, she didn't feel good in herself. Her sleep was being affected, her energy was being affected. Now, of course, there's many possible reasons for all of those things. And then she thought, this was before she came to see me. She thought, maybe I'm doing it too quickly. Let me start really, really slowly again. Really building it slowly didn't help her either. Now she wasn't seeing a doctor or a dietitian like yourself. She was trying to do this all herself because she was interested. She just wanted to, you know, have more energy and, you know, have more vitality in her life and look after her long term health. I'm sure many people listening right now are in that boat. She came to see me and said, Dr. Chachi, listen, I'm trying, I'm trying to do this. I've tried all the different ways. I feel like I'm failing. So she felt like a failure. This is why I think sometimes we've outsourced too much of our intuition to external experts because we never think the advice was the problem. We think that we're the failure. So she thought she was the failure. And I remember what I said to her, I said, hey, listen, and I appreciate your perspective on this once I've explained it, because you may or may not see it the way I do, but the way I saw it was I said to her, listen, no piece of health advice, no matter how good in my experience, always applies for every single person. If you're interested, why don't you let me help you figure out what might be the best approach for you at this moment in your life. And over a few weeks of her playing around with a few things that I suggested, she discovered that for her, a more lower carb style of eating, nothing aggressive, but a more lower carb style of eating with 5 to 10 different plant foods in a week, was feeling really good. Okay, so when she was eating like that, she had energy, she had focus, she was sleeping well, she didn't have any bloating, she was opening her bowel, she was having a poo. Sorry, effortlessly, right? Every day. And then I did her blood tests. They were really good. Her HbA1c, the average blood sugar measure, was looking really good. Her inflammation levels were looking really good. Her lipids were looking really good. At that moment in her life, it was very hard for Me to make the case that you should be going up to 30 plant foods. I'm not saying that couldn't happen in five years time, or maybe she needs to repair her gut microbiome and maybe she can tolerate more in the future. But one of the problems for me with advice like this that we think is generalized, that we think applies to everyone is, is that if you try and do that advice and you can't, you feel like there's a problem with you, which maybe it just ain't the right advice for you. What's your take on that?
A
So I think you're totally right, that I think we've outsourced from our intuition far too much. And I think that then becomes problematic. And when I talk about your intuition, it's really listening to how's your body feel, but also things like your hunger and your fullness levels. You know, your body has a lot of wisdom and really being able to tap into that is really just a key pathway to understand what is right for you. There are definitely kind of guiding principles, I think for most people in terms of, yes, we want to be eating kind of more fruits and vegetables and more whole grains when it comes to our gut microbiome. You know, really thinking about foods that are kind of high in fiber, but very much starting from a place that is right for you and really thinking about where you're at in the here and now. And then thinking, okay, what are the things that I can incorporate that are making me feel great? And I think a lot of the time with these advice it becomes too black and white that you either have to kind of hit that 30 plants and if you don't, then you're a failure. And I think we have that a lot with many other different pieces of advice as well. Whereas actually the most impactful thing you could be doing is just making a small regular change that you can keep up, that you think tastes great, that you enjoy. That's equally important and that is incredibly practical. And maybe some days that change isn't so easy and that's okay. And then next week you can get back on and think, okay, well, I'm going to actually add this in and maybe I'll add something else in as well because I'm kind of in that right frame of mind.
B
Yeah, no, I love that. I'm a huge fan of small changes done consistently. Start where you're at. See what is the right approach for you at this moment in time. Time it may change in the future. But I just want to talk about what you just said there, you mentioned whole grains. Okay, so there's a lot of evidence on the benefits of whole grains and what it can do for a gut microbiome and many other aspects of our health. I guess where my view is evolving because I'm always looking at what's working, what's not working. You're right. What has worked with patients, what hasn't worked with patients. And so over the course of my career, Emily, I have seen people thrive on a variety of different diets. Yes, there are some common principles. Most minimally process as much as possible. Whole food is close to natural form, you know, trying to not have excess added sugar. All those things for sure, like broad framework principles. But within that I've seen all kinds of different things. So I've seen some patients thrive on a whole food plant based diet, but I've also seen patients thrive depending on their state of health, on a low carb diet. And so therefore I look back and go, okay, wanga, what's going on here? Well, maybe there is no one perfect human diet that works for every single person. Maybe there are some principles to follow, but we have to personalize those principles for any individual. So if we think about the gut microbiome and we say that a diverse microbiome, and we get a lot of that diversity from plant foods, is good for our health and our well being, I think we also need to be able to explain when there are outliers to that where that's seemingly not the case. Right? So I've seen some patients who are not having loads and loads of fiber and they are thriving. I acknowledge that there's great evidence on fiber, Right? So I'm not saying there isn't. I'm just like, yeah, but there are some patients I know, honestly, I've been doing this for a long time. I'm like, I cannot make a case that you are not thriving. Like, there's one lady I know who is really, really low carb. She doesn't have many vegetables and fruits at all. And I don't know anyone with more focus and energy and cognition. And she's sleeping well and her A1C is amazing and her lipids are amaz amazing. So for me, I'm always thinking, with the state of gut microbiome research, what do we know? But also what do we not know yet? So I guess what I'm trying to share with you is I agree with you that fiber is very, very beneficial. But how do you explain why it is that some people are seemingly doing quite well without much fiber in their diets. Foreign the mental wellness app Calm are sponsoring today's show. Now with the start of every new year, talk of resolutions starts to creep into our lives. But without a plan, well intentioned resolutions can lead to frustration and anxiety. This year, why not try a new approach with Calm, in just one week, you can build a strong foundation for 2025 and gain confidence along the way. Calm is the number one app for sleep and meditation, giving you the power to calm your mind and change your life. Calm recognizes that everyone faces unique challenges in their daily lives and that mental health needs differ from person to person. And since self care practices are so deeply personal, Calm strives to provide content that caters to your own individual preferences and needs. Their meditations range from focusing on anxiety and stress, relaxation and focus to building habits, improving sleep and taking care of your physical well being. Calm also has sleep stories, sleep meditations and calming music that will help you drift off for some restful sleep. For listeners of my show, Calm is offering an exclusive 40% off a Calm Premium subscription at calm.com forward/livemore and new content is added every single week. Go to C-A-L-M.com forward/livemore for 40% off unlimited access to Calm's entire library. That's calm.com livemore before we get back to this week's episode, I just wanted to let you know that I am doing my very first national UK Theatre tour. I am planning a really special evening where I share how you can break free from the habits that are holding you back and make meaningful changes in your life that truly last. It is called the Thrive Tour. Be the architect of your health and happiness. So many people tell me that health feels really complicated, but it really doesn't need to be. In my live event, I'm going to simplify health and together we're going to learn the skill of happiness, the secrets to optimal health, how to break free from the habits that are holding you back in your life. And I'm going to teach you how to make changes that actually last. Sound good? All you have to do is go to drchatterjee.com and I can't wait to see you there.
A
So I'd probably say that, you know, fiber comes from many different plant foods. You know, we've got fruits, vegetables, nuts, seeds, beans, legumes, whole grains. You know, if you are perhaps feeling better by focusing more on fruits and vegetables, you know you're still getting a significant amount of fiber from that. I think what's really interesting is that perhaps a lot of the problems that people are having when it comes to fibre actually might be more related to what's called fodmaps from Monash University. Really kind of identifying that these fermentable sugars can cause people to feel a bit uncomfortable. And I think for many people, they then think, oh, I need to cut that out. But actually, it's about working through that. Systematically finding which foods kind of help you to feel okay, can you have the ones that are perhaps a bit problematic, but in smaller quantities and just kind of avoiding stacking them. So that's one group, I would say. You know, there's also kind of other groups where, as you say, that if you're finding a way of eating that works for you, that you feel healthy, your metrics are healthy. You know, realistically, there's no perfect one diet for everyone, as you say. It's about finding the diet that you can stick to that has those healthy principles. And I think we have so much kind of warring between all these different diets, saying, well, this one's best, this one's best. I'm like, the one that's best for you is the one that you can stick to that is what the best one is and that you feel great on.
B
Like, no one generally is gonna follow something in the long term if they're not feeling good on it. No one likes to feel full and really bloated. Do you know what I mean? I mean, yes, they might have to work through some things, but. But in the long term, no one's gonna do that. Cause it doesn't feel good, though, I would say.
A
And I do feel like I talk in defense of some bloating because I think we've become almost like too afraid of any bloating whatsoever and thinking that any bloating is a problem. We're actually having a small amount of bloating in that hour after a meal is actually a sign of actually a very happy gut microbiome. Because what happens when you've got microbes feed on the foods they love, so particularly fiber, but also they feed on things called polyphenols, which are kind of colors that are found in pigments that are found in fruits and vegetables. And they feed a kind of other things as well. They make those molecules for your health, but as a side effect, they make gas. So you're effectively kind of throwing them a bit of a kind of, you know, digestive party. And, you know, they're letting off a few fireworks. But that's Actually a good thing, right. When bloating becomes problematic, it's when bloating is staying high throughout the day, it feels incredibly uncomfortable. It's not going down. That's where it's like, okay, can we step back and think, is there perhaps a food intolerance or is there something else going on and how can you kind of ease that? Or perhaps it's stress related. It might not even be food related.
B
It's so often stressful. I said it really is. I love that. I think your next book should be called In Defense of Bloating. I think it's something that you're right, you know, it's almost become something that no one wants to ever experience. And I think what you said makes a lot of sense. And if I just sort of weave that in with other themes that we speak about on this podcast quite regularly. There's been quite a lot of guests recently in the movement world, like Helen hall or Lawrence Vanlingen, who have been talking about the importance of not holding your belly in because of what it does to your breathing patterns. You can lead to dysfunctional breathing patterns. But, you know, when you breathe in, your belly should actually go out. But because of this societal conditioning, people are not doing that anymore. People are holding their bellies in. Right. It's because, you know, we don't want our belly to go out. That's causing issues with breathing, which can cause issues with anxiety. And you kind of painting a similar picture through the lens of gut health, which is a bit of bloating after eating, is actually pretty normal.
A
Absolutely. And I think, you know, as you say, we're conditioned to think that we must have a flat stomach and that at all times. At all times. And that, you know, our bellies cannot move at all. And then, as you say, if we're wearing tight, restrictive clothing, we know that if you kind of have bloating, that can be, you know, make bloating much worse or can potentially cause bloating for some people because it's is restricting your digestion. And, you know, really, actually, again, that movement piece, if you're feeling that you are blip, bloated, what about going for a walk afterwards? You know, let it all out outside, which is, you know, really healthy and great for you as well.
B
So celebrate the bloat. I love it.
A
Celebrate a little bit of the bloat. Make peace with it. And yeah, if you need to go for a walk afterwards, just ease off.
B
Let's get some of your practical advice. You've got some really cool Mnemonics that I've read about in your book, I've seen you talk about in some of your videos. If someone wants to say, hey, Emily, listen. Okay, I get it, you know, the gut microbiome is important for many aspects of my health. What can I do to improve my own gut microbiome with the acknowledgement that we're all unique and we have to personalize things for us. If you could maybe walk us through some of your mnemonics to help us take away a bit of practical advice, that would be useful, I think.
A
Absolutely. So I think the real key piece, as you say, depending on what works best for you, but fibre is something that we're drastically missing in the UK diet. So we're missing about 40% of that recommended 30 grams of fiber that we need a day. And I find this fascinating because, you know, we're so obsessed with talking about protein. Protein, you know, shakes, bars, it's everywhere, high protein. And actually most of us are getting enough protein as it is, but we're actually missing on the fibre. It's this forgotten nutrient that we need to be paying attention to. Now, what happens with fibre and your gut microbiome is that fibre feeds your gut microbiome specifically to specific types of fibre called prebiotic fibres. Now these are fibres that are found in beans, they're found in onions, garlic, leeks, asparagus, lots of different other foods. And when your gut microbes feed on this fiber, they're able to make those short chain fatty acids which have an anti inflammatory effect and able to signal to your brain and lots of other healthy molecules as well, which support the health of your gut barrier lining and also are able to then travel into your bloodstream and going across your body to your different organs. So fibre is something that I really feel quite strongly that it's had this, this kind of boring reputation of just something that just kind of helps you go to loo, helps you do a poo. It is so much more than that.
B
So it needs new pr, basically.
A
It needs new pr. Absolutely. You know, it helps with your heart health, it helps to soak up bad cholesterol for that to be removed from your body as waste. It helps to balance your blood sugar levels, giving you longer lasting energy. So it's not only just helping with your gut microbiome, it's having many other benefits that's in your body too. And when I talk about fibre, the key foods that I really want to talk about are what I call the BGBGs. So BGBGs that's beans, greens, berries, grains and nuts and seeds. And in particular, what might surprise people is actually the highest fibre foods are whole grains, nuts and seeds and beans. Much more so than most fruits and vegetables, which I think is quite counterintuitive for some people, I think. Oh, well, actually, you know, lettuce, you know, I need to be eating salad for days, actually. Lettuce contains about 1.8 grams of fibre per 100 grams. In comparison, chickpeas has about five times, six times more than that. Something like the nuts and seeds, for example. Let's compare that to flax seeds or chia seeds. That's about 25 to 30 grams of fibre per 100 grams. So really, really big jump. And what I really want to highlight with that is that it shouldn't feel stressful to add more fibre into your diet. It's about making these BGBGs, you know, an everyday or most day foods. I really say it doesn't have to be every day, but kind of adding them to your essential shopping list. And that just gives you kind of an easy kind of fiber boost on a daily basis to feed your gut microbes and look after the health of your gut. Because a healthy gut also supports a gut microbiome.
B
Yeah, I love that. And just to circle back to something I said before, I think it's really, really relevant here. Fiber comes in a variety of different places. Right. So I was telling you about someone I know very well, a good friend of mine who is absolutely thriving on a very, very low carb diet. Sure. If you saw her as a patient, you'd be like, why would you change anything when you're functioning like this and your blood tests look like that? Right now I'm now thinking through to her diet from what I know. And although it's very low carb, she does have a lot of nuts. Okay. She does have quite a bit of black coffee. She does have tomatoes often with some herbs. Right. She has olive oil a few times, which she'll have some sweet potatoes. Right. So what I'm saying is that we have a perception of what high fiber foods are. Just from what I've said to you there, without knowing this lady's history and everything about her, although on the face of it, it's quite a low carb diet and it is, I guess there's probably not as much fibre there as you might want someone to have, but there is some fiber there and there are some plant foods that will be helping her microbiome. Is that fair to say?
A
I think it Sounds like she probably is having more fiber than we think because I think we associate fiber with being just like, you know, boring bran bread. We're able to list off high protein foods off the get go. I'd say I can ask anybody. Tell me three high protein foods they know. They could say, you know, meat, fish, eggs, straight away. When I say the same for fibre, people draw a blank. And I really think we need to change that and really recognise that, you know, fibre is found in lots of different other, you know, so many different plants. You know, fruits, vegetables, beans, legumes, nuts, seeds, whole grains.
B
Why don't you share with us your five favorite high fiber foods?
A
So I want to share the surprising ones actually, because I think that's always quite fun. So avocado I think we associate with kind of this gorgeous, rich, kind of really good of healthy fats. One Avocado contains about 8 grams of fiber.
B
Okay, My friend who I was talking about, she has an avocado every morning.
A
There we go.
B
Do you know what I mean? So that's low carb, but it's high fiber, right?
A
And then dark chocolate is a great one. That's about 11 grams of fiber per 100 grams. So I usually go for something ideally 70 above in an ideal, optimal world, kind of 65%. I am a huge fan of rye pump nickel bread, which you know is affordable. You can get it from the supermarket and effectively it's that really flat bread that contains a lot of, kind of has a lot of seeds in it quite often as well. And I really like that because one slice of that is seven grams of fibre. So you know already that if you're having that for breakfast with some eggs, with your avocado, that you're hitting probably about 10 grams, a third at breakfast. At breakfast, already a third of your fibre. So those three foods are kind of surprising. I do think some really great ones to have are nuts and seeds. Again, I just want to kind of highlight the kind of chia seeds, flaxseeds, you know, even something like a kind of dried coconut flakes. Again, really high in fiber. What I like to do is have a jar of them by the kettle and that means that I can see it. It's gonna prompt me if I'm making a cup of tea, I can have them as a snack. But also they're really great to sprinkle onto your breakfast in the morning or perhaps toast them, put them into a salad or on top of your veggies.
B
You talk in your book about breakfast being a gut Health opportunity.
A
Absolutely.
B
That's interesting, isn't it, where, you know, instead of thinking of breakfast as something we're doing to just get us going for the day or to break our overnight fast, you're. I guess it's giving it that sort of PR makeover, saying, no, no, this is a gut health meal if you do it the right way.
A
We see people who skip breakfast tend to have less fibre and have a lower intake of many kind of micronutrients. Again, of course, this is very individual. You know, I've got some people who able to just have, you know, really kind of nutritious fibre rich diet and the rest. But I have to say it does make it a lot harder because fibre, while it's found in many different foods, we do need to be really making sure that we're getting in the right amounts to really hit that 30 grams of fibre a day. And if we're taking out a meal, that makes it much, much harder.
B
One of the recommendations you make in your book is to have or to aim for half of your plate being vegetables.
A
So it could be, I say vegetables mainly, but it also could be fruit, for example, if it's breakfast. And I think for me it's really about, really about mental load when it comes to health advice and what we're doing. You know, do we want to be spending a lot of time overthinking or weighing or measuring something that is not, you know, that's stressful? We don't have time for that. So for me, it's about those simple practical approaches that you can literally just look at your plate and say, okay, half of that is vegetables, half of that is fruit. For example, whichever way you're going, or perhaps you're having a bowl of fruit at the end of the meal. That's just such a simple thing that every one of us can do without thinking about it. That means that we're getting more of that fibre in. And then of course, those fruits and vegetables also contain all those other nutrients that we need for our health.
B
Do you make a distinction between starchy vegetables and non starchy vegetables, or does that depend on your patients?
A
So I say I didn't necessarily include potatoes in that definition because, you know, they're starchy vegetables, starchy vegetables. And I think, you know, potatoes are actually, you know, really satiating and, you know, there's lots, especially in the skin, lots of nutrients, but I think we do tend to think of them in the kind of everyday person as a carb rather than as a vegetable. So for Me, it's about anything that we consider as a, as a kind of carb in our day to day. Let's just, you know, put that, you know, maybe a quarter of your plate and you know, really have those, those greens and those different colours.
B
Yeah, I would say for many years I've tried to have half of my plate being non starchy veg. You know, I think it's, I don't always manage it, but it's just a nice way of. And I've used that recommendation with patients for years and it's, it's really quite helpful. Particularly I would say in a world where many people are now carrying excess weight and have insulin resistance and are pre diabetic or even type 2 diabetic. Again, there are many ways to tackle that, of course, and you can have starchy vegetables on a diet and still tackle those things. But I found for many people it's really helpful to really focus on a lot of those non starchy vegetables to fill up your plates. You know, you get full, there's a lot of fiber in it. You, you tend to eat less of the other stuff because it's so filling. I guess you're saying that you find that quite useful, like not including potatoes in those recommendations. Would you include sweet potatoes in that?
A
Oh, I think sweet potato gets bounced back and forth. I think sweet potato can realistically probably go and eat it because it's got that dark orange colour, you know that you're getting kind of extra polyphenols from that, which are also good for your microbiome and important for your health.
B
Okay, so fibre is one of these big things that you want to encourage people to think about.
A
Yeah, absolutely. And I think, you know, there's other compounds that we can also think about when it comes to our health and for the health of our gut microbiome too, particularly talking about compounds called polyphenols. So polyphenols are these kind of compounds that give fruits and vegetables a lot of their pigment and colour. So that could be, for example, the deep purple of an aubergine and then kind of comparing that to kind of another fruit and vegetable of a different colour. And what these different groups of polyphenols tend to do differently, different things for our health. So this is why we want this rainbow of foods, we want this variety of different colours for our health. What happens with our gut microbes that they feed on these polyphenols in a similar way to fiber. So that helps to also support the health of our gut microbiome in the uk, most of our polyphenols come from coffee and tea. So coffee and tea are great sources in themselves, but in comparison to herbs and spices, they're pretty low on the list. Other surprising foods that are really rich in polyphenols and incredibly affordable are things like beans, particularly black beans. And I like to say this because I think quite often when we think about kind of polyphenol rich foods, you know, somebody might say, oh, I need to go and buy some wild blueberries, which cost, you know, an absolute fortune. But actually, things like black beans contain about eight times more polyphenols than wild blueberries. And you're then getting something that is affordable that's doing great for your health. And yes, you can still have those blueberries, but you don't feel like you have to go and spend three times as much to be doing it.
B
Yeah. And I think that's one of the plus sides of thinking about a lot of these foods that we think are supporting a healthy microbiome, like the prebiotic fiber foods you were mentioning before. Onions, garlic. I don't know if you mentioned Jerusalem artichokes, because that's in the top five list that was published a couple of years ago. These are relatively cheap foods. I appreciate everyone's got different income levels and different levels of access, but they're not the most expensive foods, which I think is quite encouraging. If people are trying to make small changes to have an impact on their health, it's like, well, you could start there and you're gonna start to see a difference.
A
Absolutely. And I think we've overcomplicated gut health far too much. It's been made out to seem that we need to have this supplement or kind of that latest new thing that's come out. And actually it's those core key principles are doing the best things for your gut, and that is just maybe it's adding in some onions and garlic to. If you're making a stew or a soup, perhaps it's sprinkling on some extra herbs or some nuts and seeds next time you have your lunch. Like, really simple, practical things, those are the things that are actually making the biggest impact for your health.
B
One thing I think a lot about when I think about gut health, I think about all this modern science and the new measurement techniques. We now have to look at gut health. And yes, all this advice now on how we can improve our gut health and things we're talking about fermented foods, kefir kimchi of different levels of expense depending on how Much you want to spend, how much you can spend. Right. And then obviously supplements and all that kind of stuff. And I think this is sometimes a little controversial for people, and I'd love to know your take on this. Are we having to focus on gut health in the 21st century so much because the default has become so unhealthy? Right. So let's back up 50 years, right. Where we didn't have the same level of access to ultra processed foods. We didn't have as much chronic stress as we're now seeing in, you know, many countries where people were more active and less sedentary than they are today. Right. People were sleeping more than they are now. We know all of those four things, the four pillars, as I call them, impacts our gut microbiome in a world back then. Right. And I know we're not in that world. But as a thought experiment, if you are mostly eating an unprocessed, non ultra processed diet, which I know most people are not, but if you were, and if you were sleeping well and had low levels of manageable stress and were maybe walking for an hour a day, I wonder if you would have to focus on gut health as much or whether your default state would actually be pretty good gut health.
A
I think if you're already doing those foundations for gut health automatically, then inherently you're having a better health status and your gut microbiome is happier. Then we tend to focus on the things that could potentially go wrong. I think we're drawn to potential issues and I think we recognize that the food environment that we're in, you know, we have an onslaught of marketing from different companies. Even walking through a supermarket, you know, the particularly, you know, the way that the supermarket is structured is, you know, what's called nudging. They purposely place the eggs at the very end so that you walk through the crisp aisle, for example, you know, there's very kind of strategic placement of kind of food and food products to make you buy because it's a business. But that inherently means that those things can end up in our shopping bags and therefore on our tables. And I think, you know, it's very difficult because how much autonomy do we have? Yes, we have some autonomy, but there is so much that is actually subconscious that is happening and driving these food choices.
B
Yeah. And a lot of people, of course I do acknowledge this, are, you know, really struggling. Right. They are under chronic stress, they are sleep deprived, they're having to work more than perhaps they want to, to keep the lights on at home, to keep the Heating on. Right. That is very real. For many people it was more. It's not to deny that. I know that's real and I know we need help with our gut's health. It's just this broader philosophical point, like I suspect like a lot of the so called blue zones, right. These populations around the world where they're seemingly living to, you know, a ripe old age and really good rates of health. They are having really good gut health or they had really good gut health, but they weren't thinking about their gut health. I don't think they were actively thinking of, oh, you know, I better increase my fiber, I better increase my polyphenols, I better do this. Actually, they were living a life that naturally was resulting in good quality gut health. That's kind of the point I was trying to get at.
A
Yeah, I think we want to be in that state of health where we don't have to think about health. Right. And I think that's perhaps, you know, just carrying on from your point there where you know, these communities are, you know, I mean these communities are communities, you know, they are interacting with each other, they're spending a lot of time outside, they're doing exercise. You know, that is just things they're doing for pleasure and for joy that make them feel good. That's very intuitive that perhaps we stepped away from and are now doing those things because we think we should and actually we need to get back in touch with those things being what make us feel good and that we enjoy them and very much that being a key purpose that we should do it for pleasure too.
B
Yeah. What's your take on time restricted eating and early dinners?
A
So again, early science coming around this, I think we see mostly from the evidence that we do have that having a kind of eating window. So that's, you know, from the time that you first eat something in the morning to you last eat something at night, being a period of about 10 to 12 hours. And that just means that that is associated with a more diverse microbiome, but also better mood, better energy and also better cognition as well. And I think really when we think about that, we think about the fact that if you're eating really late, so we know that if you eat within the hour before you go to sleep, that can impact your sleep, but then that impacts how you feel the next day. There's also been a kind of small, tightly controlled study where they looked at people who ate at 6pm versus 10pm and the people who ate at 10pm had higher levels of cortisol which is the stress hormone. So really just thinking about why might this be likely? It's because our body runs on its body clock, as does our digestion is in tune with our body clock and we respond to light and night and day. During the daytime our body knows that it's awake, that that is the time that when we're going to be eating. And at nighttime our digestion is still happening, but it's just slowing down, it's getting. Your body is relaxing, ready to go to sleep. So really trying to focus, you know that eating window on. Yes. Trying to maybe perhaps have your breakfast and then perhaps eat dinner a little bit earlier. But I think I really kind of share this with people that find what works well for you within your life and lifestyle patterns. And none of this advice is ever a rule. It's what is appropriate for you that fits in your lifestyle that makes you feel good. And I very much talk about things as being kind of most days rather than every single day. And an example for that might be, you know, I've been vice to go out for dinner, you know, on a Friday night and I'm going to go out with my friends and have a nice dinner at an Italian restaurant. I'm not going to say, oh, I can't come because I'm meant to be honouring my time restricted eating. Like that's an unhealthy choice to say that you're not going to go and spend time with friends and family.
B
Yeah, interesting. I think time restricted eating is one of the most powerful interventions I've seen in my years as a clinician. It really is. I think it's a simple thing that for most people is doable. Like you mentioned an eating window of 10 to 12 hours. Let's even make it super simple, call it 12 hours. Right? Where from the moment you take your first bite in the morning to your last bite is 12 hours. So you know, that could be 8:00am till 8:00pm or yeah, I probably do. 10, 11 hours I think, you know, I try and do, you know, breakfast at 8am, finish eating dinner by 6pm I have children, I like to eat early with the children. It's what works for me in the context of my life. But I have seen it even when there was early science in only mouse studies. Maybe in. When did Satchin Panda first start publishing this? Maybe 2014, 2015, something like that. I thought this kind of makes sense with what I know about circadian biology. I can't see any real downside here. Why don't I try it with certain patients and see if it helps. Obviously all kinds of improvement. Sleep would get better. Ibs, irritable bowel syndrome. Wow. So many people improve their IBS symptoms when they go to some form of time restricted eating, in my experience. So I think it's a, I think can be really helpful. I appreciate you sharing the science of what it can do for the gut microbiome. I think a lot of the benefits may also be mediated through better sleep.
A
Yeah, absolutely. We know sleep is so important and also that sleep then impacts your eating behaviours the next day because if you're tired, you're then more drawn to things that are perhaps less healthy for us and then it becomes this kind of self fulfilling cycle.
B
I think anyone who's ever had a sleep tracker and the pros and cons of sleep trackers are maybe beyond the scope of this conversation. But I think one of the things they can teach people is the effect of eating close to your bedtime and what it does to the quality of your sleep. You know, few years ago when I got my very first sleep tracker, that was probably one of the key learnings for me alongside what alcohol can do to your deep sleep was like, oh wow. If I'm eating within an hour of bedtime or even for me within two hours of bedtime, you can see it in your sleep quality and feel it the next day. So although it can be challenging sometimes, I know I'm my best version of myself when I can stop eating three hours before bed. Now I know for some people that can be really challenging, especially cause of modern life. Right. Because you know, that evening meal is often when we down tools and we, you know, connect with our family and our partner and whatever it might be. Right. So that often can be by the time someone's commuted home or you know, it's often late in the evening or later than you might want. So I guess we have to be mindful of that and understand that not everyone can do it. But generally speaking, I think an earlier dinner time tends to be better. Would you agree with that?
A
Yeah, I definitely am in that club of thinking it's better to eat earlier for dinner. But of course, as you say, within what works for you. But I think for the people who are thinking about trying this and seeing whether it works well, you know, even something like bulk prepping at the weekends, if you've got time, you know, getting some meals that are already happening, that could be something like I'm just gonna roast a pan of roast vegetables and then you've got that ready to go. Then you can add that to some whole grain couscous and maybe some fish that'll maybe take 15 minutes to cook. But also things like really recognizing the power of leftovers. I'm a huge fan of leftovers and repurposing that. So it could be that maybe you've made a really nice kind of warm salad for the day before. You've made it with kale and with nuts and seeds and you've got maybe some chicken and some feta in there and some avocado. You know, could you have that as a side for your meal at dinner time, perhaps the next day? Or if it's some other something else, can you add some chickpeas to it and make it into a more kind of substantial, hearty meal? Lots of different things you can do. But I really think that leftovers get kind of forgotten as like a health tool that we can. Can really tap into.
B
What's the relationship between alcohol consumption and our gut microbiome?
A
So alcohol is, unfortunately for us, wanting to enjoy kind of an occasional tipple is not really that great for our gut and our gut microbiome and also for our brain as well. We're seeing even a small amount of alcohol isn't necessarily very good for us. What's happening with alcohol in the gut is it starts to kind of irritate the gut lining. And I think anyone can relate to this. Perhaps, you know, in your youth when you had maybe a few too many drinks, you know, you then need to kind of dash to the loo and you've got kind of a change in your. Kind of in your poo, basically. So that is not necessarily something that your gut microbes like. What I do say is that we've got to be realistic, that I'm not going to say everyone needs to swear off alcohol. If you are going to choose an alcohol for your gut microbes, likely red wine is the best option. That's because we think it's so rich in polyphenols, more than kind of many other alcohol types, because of that deep purple red colour, giving that colour from the polyphenols to the red wine. What we see from some research is that red wine in small amounts, so about one glass a day maximum, is associated or linked to a more diverse kind of healthy microbiome.
B
Than what? Than someone who's not drinking, than if.
A
Someone is having kind of other alcohol types.
B
Okay, so you're comparing within alcohols, within alcohols. Got it. Because I guess what you're not saying is if you don't drink, let's say someone doesn't drink alcohol at the moment, for whatever reason. I don't think you're saying it would be good for you to start drinking red wine for your gut microbiome. No, no, Just want to clarify that.
A
And I think basically, if you're looking for a polyphenol source, there are many other sources of polyphenols that you can.
B
Be getting without the downsides.
A
Without the downsides. But if you are an alcohol drinker, then perhaps, you know, if you are gonna drink alcohol, then choose a red wine if that's a choice that you're gonna make. But ideal world, we would not need to be drinking that much alcohol. Cause it's not great for us.
B
For us. I'm really interested in how our gut microbiome changes throughout our lifetime. In the book, you say that the longer you live with someone, the more similar your gut microbiome can grow to be. That's really interesting because, you know, as of a few weeks ago, I've been married for 17 years, so a long time. Right. And it's amazing how well, you know, whilst you remain different people with your own preferences and your personalities, you know, it is amazing how you do kind of take on a few elements of the other person. You know, you spend 17 years together, you know, things are going to morph together. So it's interesting that how you might start to have similar gut microbiomes. Of course, it makes sense on one level, in the sense that your, you know, depending on how much time you're spending together and what you're doing with that time, you're, you know, you're probably eating similar foods, touching similar surfaces, right? And all that kind of stuff. So that's one aspect I wanted to talk to you about, the other aspect related to how our microbiome changes. And I'm asking you because you're a microbiome researcher, someone like me, who is born to Indian immigrants. So, you know, Mum and dads, when they came to the UK in the 1960s and 1970s, they had never left India before, right? So they would have been eating traditional foods. Like my family in India, in Bengal, would have had meat and fish and vegetables and rice and lentils. There's a perception of Indians are vegetarians. It's not true. Many are. Many are not as well. So in West Bengal and Calcutta, you know, people do eat meat and fish, okay? So Mum and Dad would have had a certain gut microbiome informed by their upbringing and being In India. So they come to the uk and then me and my brother were born here in the uk, right. And so as a kid I would eat at home, at least not at school, but at home. The foods that mum would cook, which would typically be Indian foods. Not exclusively, but typically. And so I guess I'm really fascinated. Do you know anything about how, let's say for immigrants or children of immigrants, do their microbiomes more take on the microbiomes of the country in which they're settled? So for me, I'm born and brought up in the uk, lived here my entire life. Or are they more like their parents microbiomes? Is there any research on that at all?
A
So there was a study done in the US a few years ago. And what they looked at Thai immigrants coming into the US and looking at the generations from that that were then kind of living in the US what they saw was that their gut microbiome diversity actually started to decrease. So that was kind of, you know, seen as being a less healthy gut microbiome. And they saw that as being partly because of the shift in the foods that they were eating, becoming more kind of acclimatized to the kind of a US diet, which we've got a caveat, is typically this western style diet that isn't necessarily particularly healthy. What was really interesting is that they saw changes in the types of microbes that tend to feed on certain types of fibers. So really seeing this shift from changing from some of the foods they were traditionally eating, the gut microbiome kind of shifting and recognizing that, okay, I've got new, different fiber sources, new different foods that I need to then, you know, be able to kind of shift and be able to break down and get energy from and digest. So very much shifting and changing form to work with the new diet that was happening.
B
Wow, it's fascinating, isn't it? And I'm sure we'll probably see more research on this over the coming years in terms of the longer we live with someone, the more similar our gut microbiomes can potentially become. What can we, what can we take from that?
A
It's very much that our microbiome is perhaps outside of us as well. Our microbiome is not just inside of us. We've got a skin microbiome and then our house microbiome, which is kind of contributed to by the members of the family and the people that we live with. So yes, we might be eating the same foods and that is one part of it that's kind of causing our microbiomes to be more similar. But it's also the fact that, you know, if you were to take a family out of one house and put them in another house, that kind of microbial imprint will carry with them and, you know, that will be their surroundings as well. So there's constantly shifting and changing and of course, you know, you know, hugging and skin contact is also.
B
And 10 second kiss and 10 second kisses. Kisses, of course, yeah. Listen, I've so enjoyed talking to you. I know we've gone into all kinds of different areas perhaps to kind of wind this conversation down. I'm guessing people are already sold from this conversation on the importance of their gut health. If they're still not, give us a top line. Why should someone care about the health of their gut?
A
I think think about how you feel in the here and now. And that's really, you know, is it your mood, your energy, your cognition, you know, that is what your health is giving you. And I think we gotta recognize that your gut microbiome is playing a key role in that. Of course, it's one piece of the puzzle, but the beauty of the gut microbiome is that we're able to change it. And therefore we can improve our health by making changes to support our gut microbiome.
B
Okay, and you've mentioned a lot of tips throughout this conversation, but if you were just gonna boil it down to something quite short at the end, if someone now saying, right, Emily, I'm all in. This is the year I'm gonna sort out my gut's health, what are your top tips? What would you say to them?
A
So let's recognize that stress, sleep and movement are really important, but because I'm a dietitian, I'm gonna give you some foodie ones.
B
Great.
A
So we talked about the BGBGs. So beans, greens, berries, grains and seeds, nuts and seeds. I'm gonna count that as one being your high fibre. And then we know that hydration is really important not just for your gut, but also for your brain. So really thinking about getting enough water in, you can get polyphenol sources from tea, from coffee. And the way that you can check how hydrated you are is by looking at the color of your pee. It should be a pale lemonade colour. Then we've also got fermented foods. Fermented foods, particularly kefir. Really interesting new research coming out. Small, tightly controlled studies showing that there is this connection between the gut and the brain. Studies showing that it improves your relational memory. This is memory that you need to recognise people's faces and to remember where you left the keys. So trying to include some kind of fermented food in most of your days and I think that time restricted eating piece that we talked about earlier, you know, trying not to eat too late and giving your body time to digest before we go to sleep is going to help with your gut microbes too.
B
Amazing. Well Emily, thank you for all the work you're doing. Thank you for spreading the message of gut health all around the world and thank you for coming on the show. Really hope you enjoyed that conversation. Do think about one thing that you can take away and apply into your own life and also have a think about one thing from this conversation that you can teach to somebody else. Remember, when you teach someone, it not only helps them, it also helps you learn and retain the information. Now, before you go, just wanted to let you know about Friday 5. It's my free weekly email containing five simple ideas to improve your health and happiness. In that email I share exclusive insights that I do not share anywhere else, including health advice, how to manage your time better, interesting articles or videos that I've been consuming, and quotes that have caused me to stop and reflect. And I have to say, in a world of endless emails, it really is delightful that many of you tell me it is one of the only weekly emails that you actively look forward to receiving. So if that sounds like something you would like to receive each and every Friday, you can sign up for free free@drchatterjee.com Friday 5 Now if you are new to my podcast, you may be interested to know that I have written five books that have been bestsellers all over the world covering all kinds of different topics. Happiness, food, stress, sleep, behavior change and movement, weight loss, and so much more. So please do take a moment to check them out. They are all available as paperback ebooks and as audiobooks, which I am narrating. If you enjoyed today's episode, it is always appreciated. If you can take a moment to share the podcast with your friends and family or leave a review on Apple Podcasts. Thank you so much for listening. Have a wonderful week. And before you go, I just want to let you know about an exclusive January offer. If you want to listen to every episode without having to hear any of the adverts, you can do so with an Apple subscription. We're extending the free trial from seven days to 30 days. So if you want to take advantage of this offer and support the podcast and enjoy every single episode advert free for an entire year, just go to the Apple Podcast app and subscribe. And always remember, you are the architect of your own health. Making lifestyle change is always worth it because when you feel better, you live more.
Podcast Summary: "The Latest Science of Gut Health: What To Eat, When To Eat & Why You Don’t Need 30 Plant Foods Per Week with Dr. Emily Leeming" (#508)
Feel Better, Live More with Dr. Rangan Chatterjee
Release Date: January 8, 2025
Guest: Dr. Emily Leeming, Microbiome Scientist and Researcher at King's College London
In episode #508 of Feel Better, Live More, host Dr. Rangan Chatterjee engages in an enlightening conversation with Dr. Emily Leeming, a renowned microbiome scientist, registered dietitian, former chef, and author of Genius Gut: The Life-Changing Science of Eating for Your Second Brain. The discussion delves deep into the intricacies of gut health, its pivotal role in overall well-being, and practical approaches to nurturing a healthy gut microbiome.
Dr. Rangan Chatterjee (00:12):
"20 years ago, very few scientists even knew about something called the gut microbiome. Today, with over 70,000 research papers, this complex ecosystem... is recognized as a key factor in our physical and mental well-being."
Dr. Leeming highlights the exponential growth in microbiome research over the past two decades. Initially a niche field, advancements in technology have unveiled the profound impact gut microbes have on various aspects of health, positioning the gut microbiome as a "forgotten organ" integral to digestion, immune response, stress management, skin health, and mental well-being.
Dr. Leeming (03:24):
"We have a range of different types of microbes, similar to a company that has lots of different jobs... But the thing is, a gut microbiome test is incredibly expensive and isn't going to tell you much more than that."
Dr. Leeming simplifies the concept of the gut microbiome for listeners, comparing it to a diverse workforce where each microbe has specialized functions. While commercial gut health tests provide insights into microbial diversity, they often lack actionable advice. Instead, Dr. Leeming emphasizes observable signs, such as bowel movements, as reliable indicators of gut health.
Dr. Leeming (08:01):
"What are the key things we want to be looking for? We want to make sure that you're going between three times a day to three times a week."
Dr. Leeming elaborates on practical methods to assess gut health without resorting to costly tests. Regular and predictable bowel movements, described as smooth sausages or slightly cracked, along with a dark brown color, signify a healthy gut. Red flags include irregularity, pain, or the presence of blood, necessitating medical consultation.
Notable Quote (09:46):
"It's not just about the health of your gut... it's every single day of your life. It's not just about, you know, trying to ward away some kind of future illness."
—Dr. Emily Leeming [09:46]
Dr. Leeming (16:33):
"There's a long winding nerve called your vagus nerve. It acts like a two-way pathway between your gut and your brain."
The conversation explores the bidirectional communication between the gut and the brain, primarily mediated by the vagus nerve. Dr. Leeming explains that while 90% of the communication flows from the gut to the brain, the gut microbiome significantly influences stress levels, mood, energy, and cognition through various pathways, including neurotransmitter production and metabolite release.
Notable Quote (22:38):
"If you’re gonna have this new partner in your life... your gut microbiome, your gut could be doing some form of sensing here and going compatible, not compatible."
—Dr. Emily Leeming [22:38]
Dr. Rangan Chatterjee (67:55):
"Fiber is something that we're missing in the UK diet. We're missing about 40% of that recommended 30 grams of fiber that we need a day."
Dr. Leeming underscores the essential role of dietary fiber in maintaining a healthy gut microbiome. She introduces the mnemonic BGBGs—Beans, Greens, Berries, Grains, and Nuts & Seeds—as key high-fiber foods that feed beneficial gut microbes. Contrary to popular belief, she points out that whole grains, nuts, and seeds are often richer in fiber than many fruits and vegetables.
Notable Quote (73:42):
"Dark chocolate is a great one. That's about 11 grams of fiber per 100 grams."
—Dr. Emily Leeming [73:42]
Dr. Leeming (16:33):
"Chronic stress... impacts how their digestion is working... Your gut microbes, if you've got a healthy gut microbiome, are able to actually help you manage some of your stress levels."
The discussion delves into how chronic stress triggers the body's fight or flight response, diverting energy away from digestion and altering the gut microbiome's diversity and resilience. Persistent stress can lead to a less diverse and less healthy gut microbiome, exacerbating stress responses and affecting overall health.
Incorporate BGBGs:
Hydration:
Fermented Foods:
Time-Restricted Eating:
Celebrate Bloating:
Notable Quote (77:08):
"Veggies, mainly, but it also could be fruit, for example, if it's breakfast."
—Dr. Emily Leeming [77:08]
Dr. Leeming (35:02):
"Children, before they hit puberty, their microbiomes tend to be quite similar... With women, we then see that you get into adulthood and you've got then a slightly different microbiome to men."
Dr. Leeming discusses how the microbiome evolves with age and hormonal changes. In puberty, especially for girls, estrogen interacts dynamically with the gut microbiome, influencing its composition and function. In adulthood, men's and women's microbiomes diverge, reflecting their different nutritional and hormonal needs. Post-menopause, women's microbiomes tend to resemble men's, likely due to decreased estrogen levels.
Notable Quote (37:05):
"We need to think about looking at it from an evolutionary perspective."
—Dr. Emily Leeming [37:05]
Dr. Leeming (83:56):
"We've got an onslaught of marketing from different companies... it's very difficult because how much autonomy do we have?"
Modern lifestyles, characterized by processed foods, sedentary habits, chronic stress, and disrupted sleep patterns, adversely affect gut health. Dr. Leeming emphasizes that the current food environment, with strategic product placements and marketing, makes it challenging to maintain a healthy diet conducive to a robust gut microbiome.
Dr. Leeming (98:15):
"Thai immigrants in the US saw their gut microbiome diversity decrease... because of the shift in the foods that they were eating."
Research indicates that immigrants often experience a shift in their gut microbiome diversity as they adapt to new diets and environments. Traditional diets rich in diverse fibers give way to Western diets, leading to reduced microbial diversity and potentially less healthy microbiomes. This underscores the microbiome's adaptability and its susceptibility to dietary and environmental changes.
Dr. Leeming and Dr. Chatterjee conclude by reiterating the profound impact of the gut microbiome on overall health and the importance of nurturing it through practical, sustainable lifestyle and dietary choices. Emphasizing personalization, Dr. Leeming advises listeners to listen to their bodies, make incremental changes, and avoid rigid dietary rules that may lead to stress and unintended health issues.
Final Notable Quote (101:49):
"It's the BGBGs... hydration is really important... fermented foods... time restricted eating."
—Dr. Emily Leeming [101:49]
Key Practical Advice:
By embracing these strategies, individuals can foster a healthy gut microbiome, leading to improved physical and mental well-being.