“Virtually every aspect of health and vitality is influenced by the collection of microbes living within us. The Good Gut empowers the reader with the opportunity to embrace this leading edge science in an actionable, user-friendly way.” —David Perlmutter, MD and author, #1 New York Times Bestseller, Grain Brain: The Surprising Truth About Wheat, Carbs, and Sugar: Your Brain’s Silent Killers“We are facing a mass genocide threatening the lives of billions of people across the globe. It is the killing and harming of our own inner garden, our gut bacteria, by our processed diet, antibiotics, acid blockers and other gut busting drugs. The Good Gut for the first time connects the dots between the health of our gut flora or microbiome and our health. A bad gut causes heart disease, obesity, diabetes, cancer, autoimmune disease and more, while a good gut can prevent and heal most of what ails us in the 21st century. If you want to learn how to cultivate your own inner garden and create abundant good health, read The Good Gut!”— Mark Hyman, MD, Director, Cleveland Clinic Center for Functional Medicine, and author, #1 New York Times bestseller, The Blood Sugar Solution

“Microbes in our gut outnumber the cells in our body by more than 3 to 1. We’d better make peace with them. The Sonnenburgs show us how in their fascinating book, The Good Gut. I recommend it to everyone who eats.”—David S. Ludwig, MD, PhD, Professor, Harvard Medical School and author, Ending the Food Fight

“Sonnenburg are two rising stars in the field of microbiology and immunology research. Lucky for us, they are willing and able to put scientific jargon aside and offer us a fascinating, funny, and easy-to-read book about the latest human microbiome discoveries and how these discoveries might help us tend to our inner microbes so as to optimize our overall health.”—Daphne Miller, MD author of Farmacology: Total health from the Ground Up and The Jungle Effect

“In The Good Gut, Stanford researchers and authors Justin and Erica Sonnenburg explain some of the mysteries of the invisible world inside us. Thanks to their insight and research, the rest of us can now benefit from understanding how to improve our health by taking care of the microbes living within us.”— Mark Liponis, MD, corporate medical director, Canyon Ranch

“The 100 trillion bacteria that make up our gut microbiota represent the next great frontier in medicine and our understanding of how to obtain and maintain health. The Good Gut is a must read for anyone who struggles with health issues, from obesity to depression, and anyone looking to truly optimize their health and well-being.”—Adam Perlman, MD, executive director, Duke Integrative Medicine at Duke University

JUSTIN SONNENBURG, PhD, is currently an assistant professor in the Department of Microbiology and Immunology at the Stanford University School of Medicine. In 2009, he was the recipient of an NIH Director’s New Innovator Award.ERICA SONNENBURG, PhD, is currently a senior research scientist at the Stanford University School of Medicine in the Department of Microbiology and Immunology, where she studies the role of diet on the human intestinal microbiota.

We all know that much of our health is predeter­mined by our genes. We also know that we can gener­ally improve our health if we eat right, exercise, and manage our stress. But how to do those things is a matter of great debate. Many well-meaning health programs are focused solely on weight loss or heart health, but what if there was a second genome, one that held the key to much of our overall health, but one that we could influence by very specific (and often surprising) lifestyle choices? Well, this second genome exists. It belongs to the bacteria that inhabit our gut and is vital to our overall well-being, in countless ways. The details of how these intestinal bac­teria, known as the microbiota, are hard-wired into health and disease are starting to come to light and they are reshaping what it means to be human.As scientists try to unravel the causes behind the prevalence of predominantly Western afflictions such as cancer, diabetes, allergies, asthma, autism, and inflamma­tory bowel diseases, it is becoming increasingly clear that the microbiota plays an important role in the development of each of these conditions and poten­tially many others. Our bacterial inhabitants touch all aspects of our biology in some way, directly or indirectly. But the modern world has changed the way we eat and how we live, and as a result, our in­testinal microbiota is facing challenges that it has not experienced in the entirety of human evolution.

Our digestive system is much more than a col­lection of human cells that surround our last few meals—it also contains a dense colony of bacteria and other microorganisms. In fact, for every one human cell in our body, we house an additional ten bacte­rial cells that amount to a filibuster­proof majority that legislates much of our biology. But before you start thinking of yourself as a human being with bacterial cells inside, it may be more accurate to consider yourself as a bacterial being with a human cell coating.

More than we ever expected, the gut microbiota sets the dial on our immune system. If the gut bacteria are healthy, it’s likely that the immune system is running well. Much is being learned about how the microbiota impacts our brains. The brain-gut axis impacts our well-being profoundly, far more than just letting us know when it’s time to eat. Gut bacteria can affect moods and behavior and may influence the progres­sion of some neurological conditions.