The groundbreaking science behind the surprising source of good health Stanford University’s Justin and Erica Sonnenburg are pioneers in the most exciting and potentially transformative field of human health and wellness, the study of the relationship between our bodies and the trillions of organisms representing thousands of species to which our bodies play host, the microbes we call the microbiota. The Sonnenburgs argue that the microbiota determines in no small part whether we’re sick or healthy, fit or obese, sunny or moody—and that the microbiota has always been with us, coevolving with humans and entwining its functions with ours. They show us that humans are really composite organisms with microbial and human parts. But now, because of changes to diet, antibiotic over-use, and over-sterilization, our gut microbiota is facing a “mass extinction event,” which may explain the mysterious spike in some of our most troubling modern afflictions, from food allergies to autism, cancer to depression. It doesn’t have to be this way. The Good Gut is a groundbreaking work that offers a new plan for health that focuses on how to nourish your microbiota, including recipes and a menu plan. The Sonnenburgs show how we can keep our microbiota off the endangered species list and strengthen the community that inhabits our gut and thereby improve our own health. In this important and timely investigation, they look at safe alternatives to antibiotics; dietary and lifestyle choices to encourage microbial health; the management of the aging microbiota; and the nourishment of your own individual microbiome. Caring for our gut microbes may be the most important health choice we can make.