The bestselling author of the Wheat Belly books brings his next big, game-changing idea—how the human microbiome is evolving, and potentially wrecking, our health, and how we can fix it. Because of our highly processed diet, pesticides, and overuse of antibiotics, our guts are now missing so many of the good bacteria that we require to be healthy. As a result, many of us have lost control over our health, weight, mood, and even behavior.