Podcast Summary: "Can Fiber Improve Your Sex Life? The Science, Explained!"

Rena Malik, MD Podcast (November 12, 2025)
Host: Dr. Rena Malik | Guest: Dr. Will Bulshowitz (Gastroenterologist)

Episode Overview

In this science-driven conversation, Dr. Rena Malik, a urologist and sexual health expert, sits down with gastroenterologist Dr. Will Bulshowitz to unpack the surprising links between gut health—especially fiber intake—and sexual function. The duo addresses questions many are too embarrassed to ask, using the latest evidence to explore gut health’s relationship to sexual vitality, hormonal balance, pelvic and anal health, and more. The episode is packed with practical tips, memorable analogies, and actionable advice for optimizing sexual health through better gut care.

Key Discussion Points

1. How Gut Health Impacts Sexual Function

[01:04 - 03:05]

• Connections to Erectile Dysfunction:
  Dr. Bulshowitz highlights major risk factors for erectile dysfunction: hypertension, hyperlipidemia, and diabetes—all tied to poor metabolic health, which in turn is shaped by gut health.
  • "There's clear cut evidence that gut health plays a role… fiber has been shown to address in randomized controlled trials blood pressure and lipids and blood sugar control." ([01:13], Dr. Bulshowitz)
• Inflammation:
  Chronic inflammation affects blood flow and is a key player in erectile dysfunction. The gut regulates bodily inflammation as 70% of the immune system resides there, influencing the release of inflammatory cytokines.
• COVID-19 Changes:
  Dr. Malik observes more erectile dysfunction since the pandemic, linked to sedentary lifestyles and inflammation after infection.
  • "People are sitting more, they're getting high toned pelvic floor which is then affecting blood flow to the penis..." ([02:29], Dr. Malik)
  • "It's one of the manifestations that can occur, and they, too, typically will also manifest gut symptoms at the same time." ([02:58], Dr. Bulshowitz)

2. Psychological & Neural Pathways

[03:05 - 03:59]

• Stress, anxiety, and the balance between the sympathetic and parasympathetic nervous systems influence sexual function. Good gut health may support a healthier mental state and, by extension, sexual performance.
  • "Through the brain-gut connection, there are ways in which the gut does play a role in affecting our mood." ([03:43], Dr. Bulshowitz)
  • "In order to activate blood flow to the genitals, we need to activate the parasympathetic nervous system." ([03:29], Dr. Bulshowitz)

3. Gut Microbes, Hormones & Sexual Health

[04:06 - 05:38]

• Microbiome and Hormones:
  Certain gut microbes are linked to sex hormone production (e.g., “estrobolome” in women, Clostridium sindens in men and testosterone).
  • "There are microbes that have been found to be associated with the production and activation of testosterone." ([04:35], Dr. Bulshowitz)
• Diversity and Erectile Dysfunction:
  Men with erectile dysfunction tend to have lower gut microbiome diversity.
• Rising Tide Analogy:
  "When we elevate our health, we're rising the tide on many different aspects. And that can include sexual health." ([05:20], Dr. Bulshowitz)

4. Supplements, Minerals & Realistic Expectations

[05:39 - 07:28]

• Recommendations for boosting testosterone (e.g., zinc, magnesium, boron) are popular but lack robust scientific backing unless a deficiency is demonstrated.
  • "If you have a deficiency in zinc, magnesium, or boron? Yes...If you don't, then probably not." ([07:17], Dr. Malik)
• Testing levels and tracking how you feel is key.

5. The Impact of Alcohol and Marijuana on Gut & Sexual Health

[07:40 - 11:36]

• Alcohol:
  Can damage the gut barrier; even small amounts may hurt the microbiome and disrupt REM sleep.
  • "If you drink to the point of having a hangover, you have caused harm and damage to your gut microbiome." ([07:56], Dr. Bulshowitz)
  • "REM sleep is clearly disturbed by even one drink." ([10:04], Dr. Bulshowitz)
• Marijuana:
  Chronic use may shrink brain size and, in GI medicine, is linked to cannabinoid hyperemesis syndrome (severe nausea/vomiting relieved by hot showers).
  • "The chronic use of marijuana can ultimately lead to the development of chronic nausea and vomiting, sometimes called cyclic vomiting syndrome." ([11:03], Dr. Bulshowitz)

6. Toilet Habits, Pelvic Floor & Hemorrhoids

[11:38 - 13:19]

• Risks of Sitting Too Long:
  Prolonged toilet time can cause the venous beds (hemorrhoids) to swell, increasing disorder risk.
  • "By the age of 50, about 50% of people have these issues." ([12:22], Dr. Bulshowitz)
• Five minutes is the advised maximum—phone use in the bathroom is discouraged.
  • "Don't force it...don't sit with your phone...ideally five minutes, certainly less than 10 minutes." ([12:28], Dr. Bulshowitz)

7. Hygiene: Bidet, Toilet Paper, and Overwashing

[13:19 - 14:44]

• Bidet vs. Wipes:
  Bidets are superior; wipes can dry and irritate delicate tissues, leading to itching (pruritus ani).
  • "I'm 100% team bidet... it's also... a great way to clean the bottom." ([13:23, 13:35], Dr. Bulshowitz)
  • "That's actually the number one cause of pruritus ani, which is anal itching." ([13:40], Dr. Bulshowitz)
• Parallels drawn between over-washing in the rectal and vulvar areas leading to irritation.

8. Anal Sex: Safety, Preparation, and Recovery

[14:44 - 17:54]

• Preparation and Caution:
  Open communication, gradual progression, and proper lubrication are crucial.
  • "It's really important to...ease into it...work through what could be a period of time where it's foreplay...using toys and starting small." ([15:18], Dr. Bulshowitz)
  • "Like in the same way that we develop a callus on our feet...it sort of helps that skin to get a little bit tougher prior to moving forward with anything." ([15:55], Dr. Bulshowitz)
• Use of fiber and stool softeners for recovery from minor injuries or bleeding (Colace, magnesium citrate/sulfate/oxide recommended).
• Avoid wipes post-anal sex; use water, rest, and dietary fiber to promote healing.

Notable Quotes & Memorable Moments

• On fiber’s role:

  • "When we heal our gut, one of the benefits that we receive is improved metabolic health." ([01:37], Dr. Bulshowitz)

• On pandemic effects:

  • "People are sitting more...getting high toned pelvic floor which is then affecting blood flow to the penis." ([02:29], Dr. Malik)

• On microbiome diversity:

  • "We would discover that on average, those men [with ED] have less gut diversity compared to healthy men." ([04:43], Dr. Bulshowitz)

• On bidet advocacy:

  • "I'm 100% team bidet...I think it's one of the best things you can spend your money on, honestly." ([13:23], Dr. Bulshowitz)

• Fun Med School Mnemonic:

  • "So remember point and shoot in med school? Parasympathetic to get the erection. Sympathetic to have the ejaculation." ([03:33], Dr. Malik)

Timestamps for Key Segments

• Gut health, metabolism, and sexual function: [01:04 - 03:05]
• Inflammation and erectile dysfunction: [01:37 - 03:05]
• COVID-19 and lifestyle change impacts: [02:29 - 02:58]
• Psychological & neural pathways: [03:05 - 03:59]
• Gut microbes, hormones, and diversity: [04:06 - 05:38]
• Supplements & individualized advice: [05:39 - 07:28]
• Alcohol & marijuana effects: [07:40 - 11:36]
• Toilet habits & hemorrhoids: [11:38 - 13:19]
• Bidet vs. wipes for anal health: [13:19 - 14:44]
• Anal sex tips & tissue care: [14:44 - 17:54]

Key Takeaways

• Your gut is deeply linked to metabolic and sexual health: A healthy, diverse microbiome not only supports digestive health but helps regulate hormones and inflammation affecting sexual function.
• Pandemic-induced sedentary habits can worsen sexual function: Movement matters!
• Fiber, sleep, and minimal alcohol are foundational for gut and sexual health.
• Good hygiene means gentle washing and bidets—not wipes.
• Anal sex is safest with communication, slow progression, lubricant, and aftercare (fiber, stool softeners).

This episode is a must-listen for anyone curious about the practical interplay between diet, gut care, and sexual wellness. Dr. Malik and Dr. Bulshowitz’s science-backed tips and open, humorous dialogue make complex health topics accessible and actionable.