Robynne Chutkan, MD, FASGE, has spent three decades as an integrative gastroenterologist. She is a faculty member at Georgetown Hospital, founder of the Digestive Center for Wellness in Washington, D.C., and the author of four books surrounding the topic of the microbiome and gut health. In this episode, we discuss constructing a healthier microbiome, the concept of the “Goldilocks” immune balance, and the crucial link between the gut and the immune system. “I think it’s so eye opening for people to realize that when something is in their GI tract, it's not in their body, it's in this hollow tube… And then, of course, we have this highly selective gut membrane that is razor thin, one cell thick, and that is what is protecting us from the outside world.” Robynne describes the role of microbes in this “immune surveillance,” as well as the consequences that can arise if our immune system is unable to properly recognize and respond to pathogens. Fortunately, the microbial richness that helps train our immune response is within our control – by eating a diverse range of plant foods, we can work to build immune defenses through our diet. “We have a brilliant study from the folks at the American Gut Project in 2018 where they looked at over 10,000 people globally, and they looked at [the] dietary markers for a healthy microbiome. And they found that it was a magic number of 30 or more different plant foods per week. So people who ate 30 or more different plant foods per week had a much healthier microbiome than those who ate ten or fewer.” Here are the details of our conversation: [00:01:50] Robynne’s journey in gastroenterology and the microbiome [00:18:52] Interactions between the gut and the immune system [00:23:34] Autoimmune diseases and the “Goldilocks” immune balance [00:29:24] The innate and adaptive immune systems [00:31:19] Top 5 habits to build immune defenses [00:42:47] Improving resilience through lifestyle