191: Kiran Krishnan: How to Rebuild Your Gut Microbiome & Reduce Inflammation

What if the biggest mistake we're making with gut health is treating the microbiome like a list of bacteria instead of a living ecosystem?

Your gut is home to trillions of microorganisms that influence inflammation, metabolism, immune function, hormones, brain health, and longevity. But modern life—from ultra-processed foods and antibiotics to pesticides, chronic stress, and inadequate fiber—may be systematically stripping away the microbial diversity we need to stay healthy.

My guest, Kiran Krishnan, is a research microbiologist and microbiome expert who has spent nearly two decades studying these complex microbial ecosystems. He co-founded Microbiome Labs and has helped develop microbiome testing and clinically studied probiotics.

Kiran introduced me to the concept of the holobiome: the idea that we aren't simply human cells and human DNA, but walking ecosystems containing millions of microbial genes that perform essential functions throughout the body.

We explore what's actually damaging that ecosystem, how poor gut health can contribute to leaky gut, endotoxemia, systemic inflammation, and metabolic dysfunction, and most importantly, what we can do to rebuild it.

Kiran breaks down how much fiber we should actually be eating, the difference between soluble and insoluble fiber, why resistant starch and polyphenols matter, what fermented foods really do, and how to think about probiotics and microbiome testing. We also discuss how fasting, sleep, resistance training, outdoor exposure, and even social connection can influence microbial diversity.

In this episode, you'll learn:

• Why microbial diversity may be one of the most important markers of gut health

• How antibiotics, ultra-processed foods, pesticides, and stress can disrupt the gut microbiome

• How leaky gut, endotoxemia, chronic inflammation, and metabolic health are connected

• How fiber, resistant starch, fermented foods, polyphenols, and probiotics support the gut

• Why sleep, fasting, exercise, outdoor exposure, and social connection can help build a more resilient microbiome