<p><a href="https://peterattiamd.com/michaelgershon/?utm_source=podcast-feed&utm_medium=referral&utm_campaign=220725-pod-michaelgershon&utm_content=220725-pod-michaelgershon-podfeed"> View the Show Notes Page for This Episode</a></p> <p><a href="https://peterattiamd.com/subscribe/?utm_source=podcast-feed&utm_medium=referral&utm_campaign=220725-pod-michaelgershon&utm_content=220725-pod-michaelgershon-podfeed"> Become a Member to Receive Exclusive Content</a></p> <p><a href="https://peterattiamd.com/newsletter/?utm_source=podcast-feed&utm_medium=referral&utm_campaign=220725-pod-michaelgershon&utm_content=220725-pod-michaelgershon-podfeed"> Sign Up to Receive Peter's Weekly Newsletter</a></p> <p>Mike Gershon is a Professor of Pathology and Cell Biology at Columbia University and has been at the forefront of studying neural control of the gut for the past 60 years. In this episode, Mike gives a tour de force on the pathways of gut-brain communication but first sets the stage with an overview of gastrointestinal tract development and anatomy. He then explains how the gut communicates with the brain and vice versa, from early observations in physiology and anatomy up to our present understanding of what makes the GI tract so unique and complex relative to other organs. He talks about how the gut responds to meals of different food qualities and how that affects satiety signaling to the brain. Additionally, he explains how antidepressants and other drugs impact digestion through effects on serotonin signaling, and he discusses the effects of antibiotics, and what's really going on with "leaky gut." Finally, Mike offers his thoughts on the utility—or lack thereof—of gut microbiome diagnostic tests, and wraps up the discussion by considering how diet, probiotics, and prebiotics impact the microbiome and GI tract.</p> <p>We discuss:</p> <ul> <li>The basics of the gastrointestinal (GI) system [3:45];</li> <li>The very early development of the GI system [9:30];</li> <li>The unique properties of the blood supply and portal system in the GI tract [12:45];</li> <li>An overview of gut anatomy and innervation [16:30];</li> <li>Turnover of the epithelial lining and why cancer rarely develops in the small intestine [26:45];</li> <li>Nutrient and water absorption in the small and large intestine [30:30];</li> <li>Ways in which the gut and brain communicate [34:30];</li> <li>The gut's role in the regulation of appetite [43:30];</li> <li>The impact of gastric bypass surgery on satiety signals [51:15];</li> <li>How varicella-zoster virus (VZV) can infect neurons in the gut and create issues later in life [54:30];</li> <li>The relationship between autism and gastrointestinal illness [1:02:45];</li> <li>The important role of serotonin in the gut, and the impact of SSRIs on serotonin in the gut [1:09:45];</li> <li>Defining "leaky gut" and its most common causes [1:16:45];</li> <li>The gut microbiome [1:30:45];</li> <li>Fecal transplants: use cases, limitations, and how they illustrate the importance of gut microbes [1:40:45];</li> <li>Gut microbiome diagnostic tests: why they aren't useful outside of special cases such as cancer detection [1:50:30];</li> <li>Nutritional approaches to a maintain optimal flora in the gut [1:55:00];</li> <li>Prebiotics and probiotics, and getting your GI system back on track after a course of antibiotics [2:02:30];</li> <li>More.</li> </ul> <p>Connect With Peter on <a href="https://twitter.com/PeterAttiaMD">Twitter</a>, <a href="https://www.instagram.com/peterattiamd/">Instagram</a>, <a href="https://www.facebook.com/peterattiamd/">Facebook</a> and <a href="https://www.youtube.com/channel/UC8kGsMa0LygSX9nkBcBH1Sg">YouTube</a></p>
Actionable Insights
1. Avoid Unproven Gut Microbiome Tests
Do not rely on commercial gut microbiome tests or associated supplements, as they often lack sufficient resolution and documented evidence to provide actionable health information, and many are considered a “con.” These tests can lead to abnormally high costs and misguided health decisions.
2. Eat a Balanced, Fiber-Rich Diet
Consume a balanced diet with appropriate nutrients, including fiber, for general health and to support your gut. Avoid extreme or “cleanse” diets, as the microbiome has evolved with humans and cleansing is not beneficial.
3. Prioritize Insoluble Fiber Intake
Incorporate insoluble fiber (e.g., from celery or lettuce) into your diet, as it absorbs toxins, promotes gut motility, and provides essential substrate for beneficial colon bacteria to produce short-chain fatty acids, which energize the colon lining.
4. Prioritize Protein and Fat for Satiety
Consume meals rich in protein and fat to reach satiety sooner and reduce hunger, because these nutrients slow gastric emptying more effectively than salt and sugar.
5. Minimize High-Calorie Liquid Intake
Avoid high-calorie liquids, including alcohol, especially for weight management, as they can bypass the stomach’s satiety signals more easily than solids and undermine efforts to reduce food intake.
6. Choose Solid Foods for Satiety
Opt for solid foods over liquids to promote satiety, as solids delay gastric emptying by requiring mechanical digestion into sub-millimeter particles before passing through the pyloric sphincter.
7. Take Probiotics During/After Antibiotics
Consider taking appropriate probiotics, such as yeast-derived Saccharomyces or lactobacilli/bifidobacteria, during or after a course of antibiotics to help repopulate the gut flora.
8. Select Proven Probiotics
When choosing probiotics, look for products that have demonstrated efficacy and safety through actual tests, such as those regulated by the FTC for specific claims, ensuring the organisms survive transit and provide beneficial effects.
9. Vaccinate Against Shingles (Shingrix)
Get the Shingrix vaccine to prevent shingles reactivation, which can infect the enteric nervous system and lead to severe gut issues like pseudo-obstruction or achalasia, even if the immune system eventually clears the virus.
10. Avoid Dietary Cleanses and Enemas
Do not engage in dietary cleanses or enemas, as they are not beneficial for the body, do not kill bacteria, and can lead to dangerous electrolyte imbalances.
11. Acknowledge Stress-Gut Connection
Be aware that the central nervous system (CNS) can profoundly impact gut function, manifesting as symptoms like “butterflies,” tension-induced diarrhea, or constipation in response to anxiety or fright.
12. Understand SSRI Gut Effects
If taking SSRIs, be aware they can initially cause nausea and speed up gut motility, but may eventually lead to long-term constipation due to receptor desensitization.
13. Insight 13
Do not rely on specific dietary changes to reduce the severity of autism symptoms, as rigorous scientific evidence consistently fails to document a regular or causal relationship, despite anecdotal claims.