
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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Today's bite sized episode is sponsored by the brand new formulation of AG1, the daily health drink that has been in my own life for over six years now. Some of the upgrades in the new formula include more magnesium which supports muscle function and the ability of our nervous systems to relax. And it also now contains five instead of two strains of bacteria to reflect the latest advancements in microbiome science. It also contains key nutrients in bioavailable forms the body can easily and readily utilize, maximizing their potential benefits. AG1 makes it simple to be the best version of you over 70 ingredients, one scoop once a day for less than a cup of coffee. And right now AG1 are giving my audience a special offer worth 58 pounds which is almost 80 US dollars. You will get 10 free travel packs and an awesome welcome kit with your first subscription. To take advantage go to drinkag1.comlivemore welcome to Feel better Live More bite size. Your weekly dose of positivity and optimism take get you ready for the weekend. Today's clip is from episode 508 of the podcast with gut health expert and microbiome scientist Dr. Emily Leeming. We now know that our gut health plays a crucial role in everything from our immune system and our ability to respond to stress, to our skin and even our mental well being. In this clip, Emily shares some of the latest science along with some simple practical tips for building more gut friendly foods into your diet. Why should someone care about the health of their gut?
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I think 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 unchanged our gut microbiome, giving us another tool to influence our health. So 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 got to 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. Twenty 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, and 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, sort of these tiny living organisms that live in our gut, but also now what are they doing and how are they impacting our health. So effectively you've got 100 trillion microorganisms. So these are tiny living organisms that live in your gut. They are made of bacteria, viruses, yeasts, 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, across 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.
A
Now, the interesting thing for me about gut health, for want of a better term, is that 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, 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.
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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 we know 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. 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, 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 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. 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 fiber 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 they also need 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, 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. And I think when we, you know, the fact we go back to our microbes making up, you know, 50% of our cells, you know, they are heavily influencing pretty much every aspect of our body.
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So they're not there by accident.
B
They're not there by accident. They're playing a role.
A
Yeah. 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.
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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 fibre that we need a day. It's this forgotten nutrient that we need to be paying attention to. Now. What happens with fiber 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, 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 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.
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So it needs new pr, basically.
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It needs new pr. Absolutely, 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 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 BG B G S, that's beans, greens, berries, grains and nuts and seeds. And in particular, what might surprise people is actually the highest fiber 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 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 and 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.
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Why don't you share with us your five favorite high fiber foods?
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So, so I wanna share the surprising ones actually, because I think that's always quite fun. So avocado I think we associate with being kind of this gorgeous, rich, kind of really good of healthy fats. One avocado contains about 8 grams of fiber 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 7 grams of fiber. 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, 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.
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Yeah, I love that. And just to circle back to something I said before, I think it's really, really relevant here. Over the course of my career, Emily, I have seen people thrive on a variety of different diets. Yes, there are some common principles. Minimally process as much as possible, whole food as close to natural form, 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, Ranga, 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 personalise those principles for any individual. And 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. She has an avocado every morning.
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There we go.
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Do you know what I mean? So that's low carb, but it's high fiber. 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's 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?
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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, you know, off the get go, I'd say I can ask anybody, you know, tell me three high protein foods they know. They could say, you know, meat, fish, eggs, straight away. When I say the same for fiber, you know, people draw a blank. And I really think we need to change that and really recognize that, you know, fiber is found in lots of different other, you know, so many different plants. You know, fruits, vegetables, beans, legumes, nuts, seeds, whole grains. And then 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 does 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 fibre, 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 advice, it becomes too black and white. 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. As you say, if you're finding a way of eating that works for you, that you feel healthy or metrics or 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.
A
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. It may change in the future. Okay, so fiber is one of these big things that you want to encourage people to think about?
B
Yeah, absolutely. And I think 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. So particularly talking about compounds called polyphenols. So polyphenols are these kind of compounds that give fruits and vegetables a lot of their pigment and color. 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 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 know, 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.
A
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, you know, onions, garlic. These are relatively cheap foods. You know, 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.
B
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 that are doing the best things for your gut. And that is just, you know, maybe it's adding in some onions and garlic to, you know, 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 know, you have your lunch. Like really simple, practical things. Those are the things that are actually making the biggest impact for your health.
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Guest: Dr Emily Leeming (Microbiome Scientist & Gut Health Expert)
Host: Dr Rangan Chatterjee (GP & Author)
Episode: #575 (Clip from #508)
Release Date: September 4, 2025
This bite-sized edition of "Feel Better, Live More" explores the pivotal role of the gut microbiome in overall health. Dr Rangan Chatterjee is joined by Dr Emily Leeming, who demystifies gut health and shares actionable, science-backed dietary strategies (“3 simple tips”) to enhance gut function, energy, and reduce inflammation. The conversation focuses on why the gut is often called “the forgotten organ,” and how small, practical dietary tweaks can lead to a significant health transformation.
| Segment | Time | |--------------------------------------------------------|---------| | The microbiome as a “forgotten organ” | 02:05 | | Microbiome’s body-wide influence; evolution perspective | 05:09 | | The microbiome-brain link and short-chain fatty acids | 05:56 | | Practical advice – BGBGs and fibre | 09:18 | | Surprising high-fibre foods | 12:23 | | Diets are personal: principles, not perfection | 13:54 | | Polyphenols and the power of food diversity | 18:55 | | Simplicity over supplements in gut health | 21:10 |