#1 Gut Health Doctor: If Your Poop Looks Like This, Go To Your Doctor! - Prevent Disease In 2025

Here are the top 10 key takeaways from Dr. Rangan Chatterjee's conversation with gut health expert Emily Leeming that could transform your understanding of gut health and its impact on your overall wellbeing.

1. Checking your poop is the best indicator of gut health

Looking at your stool is a simple, free way to assess your gut health, much more practical than expensive microbiome tests. The ideal stool should resemble a smooth sausage or a sausage with cracks, with a dark brown color. The frequency should be between three times a day to three times a week, whatever is normal for you.

Red flags include blood in the stool (appearing black or red) which requires medical attention. Going to the bathroom should be easy without straining or pain, and you should feel completely emptied afterward. A healthy bowel movement shouldn't take long or require pushing.

2. The gut-brain connection is powerful and bidirectional

Your gut and brain are connected through the vagus nerve, creating a two-way communication highway. Surprisingly, 90% of the communication travels from the gut to the brain, not the other way around. This explains why gut health significantly impacts mental wellbeing.

The gut microbiome influences the brain through multiple pathways: directly through the vagus nerve, through metabolites like short-chain fatty acids, via immune system signaling, and by helping supply neurotransmitter building blocks. This complex relationship affects mood, cognition, and stress response, highlighting why gut health is crucial for mental health.

3. Fiber is an underappreciated nutritional superstar

Fiber is severely lacking in most UK diets, with people consuming about 40% less than the recommended 30 grams daily. Contrary to its boring reputation as just helping with bowel movements, fiber plays crucial roles throughout the body.

Fiber feeds beneficial gut bacteria, which then produce anti-inflammatory compounds called short-chain fatty acids. These compounds support gut barrier health, signal to the brain, and travel throughout the body. Fiber also soaks up bad cholesterol for removal and helps balance blood sugar levels for sustained energy.

4. The BGBGs framework simplifies gut-healthy eating

Emily Leeming introduces the BGBG system (Beans, Greens, Berries, Grains, nuts and Seeds) as an easy-to-remember framework for incorporating gut-healthy foods. Surprisingly, the highest fiber foods are whole grains, nuts, seeds, and beans—not vegetables as many assume.

For instance, chickpeas contain about six times more fiber than lettuce, while flax or chia seeds contain 25-30 grams of fiber per 100 grams. Making these foods part of your regular shopping list provides an easy daily fiber boost without requiring special diets or supplements.

5. Some bloating after meals is normal and healthy

Contrary to popular belief, experiencing a small amount of bloating after eating is actually a sign of a healthy gut microbiome. When gut bacteria feed on fiber and polyphenols, they produce gas as a side effect of making beneficial compounds for your health—like throwing a "digestive party" with some fireworks.

Bloating only becomes problematic when it persists throughout the day, feels extremely uncomfortable, or doesn't subside. In these cases, there might be a food intolerance or stress-related issue to address. We should resist the cultural conditioning that our stomachs must always be flat.

6. The "30 plant foods per week" rule is oversimplified

The popular recommendation to eat 30 different plant foods weekly comes from a single association in one study (the American Gut Project) rather than comprehensive research. The number 30 was chosen mainly because researchers divided participants into three groups based on plant consumption, with the top third eating 30+ plants weekly.

While diversity in plant foods is beneficial, obsessing over hitting exactly 30 types can create unnecessary stress. Some people track every plant food and avoid repeating items, leading to food waste. Instead, the focus should be on practical ways to increase variety, like choosing mixed berries over single types or stir-fry vegetable packs.

7. Sleep, stress, and timing of meals affect gut health

Eating too late (within an hour of bedtime) can disrupt sleep quality and raise stress hormone levels. Research shows people who ate dinner at 10 PM had higher cortisol levels than those who ate at 6 PM. Our digestive system operates on a circadian rhythm, working optimally during daylight hours and slowing down at night.

Time-restricted eating (limiting food intake to a 10-12 hour window daily) is associated with better gut microbiome diversity, improved mood, energy, and cognition. However, flexibility matters—occasionally eating late for social gatherings is fine. The goal is developing sustainable habits, not rigid rules.

8. Gut microbiome diversity changes throughout life

Children's microbiomes are similar regardless of gender until puberty. Girls experience significant changes related to estrogen, while boys' microbiomes change less dramatically with testosterone. Adults show gender differences in microbiome composition, with women's microbiomes becoming more similar to men's during menopause.

Interestingly, people who live together develop increasingly similar gut microbiomes over time. This happens partly because they eat similar foods, but also because they share environmental microbes in their home and through physical contact. Social connections, including kissing (which transfers 80 million bacteria in a 10-second kiss), impact our microbiome.

9. Personalization is key for gut health approaches

No single dietary approach works for everyone. While research supports the benefits of fiber, some individuals thrive on lower carb or lower fiber diets. What matters most is finding a sustainable approach that makes you feel good and shows positive health markers.

Some people may need to start with lower fiber intake and gradually increase it. Others might need to identify specific trigger foods using approaches like the low-FODMAP diet. The best diet isn't necessarily what research suggests works for most people—it's what you can stick with long-term while feeling your best.

10. Commercial gut health tests have limited practical value

Expensive commercial gut microbiome tests have significant limitations. They only tell you which microbes are present and their diversity, but don't provide actionable advice for improving gut health. What matters more than which specific microbes you have is what they're doing—the metabolites they produce that affect your health.

A healthy gut microbiome isn't just about diversity but also resilience—the ability to recover quickly after disruptions like infections. Rather than spending money on tests, focus on foundational habits: eating fiber-rich foods, managing stress, prioritizing sleep, staying hydrated, including fermented foods, and respecting your body's natural rhythms.