In this groundbreaking book, Dr. Mosley takes us on a revelatory journey through the gut, showing how junk food and overuse of antibiotics have wiped out many good gut bacteria, leading to a modern plague of allergies, food intolerances, and obesity. Your gut is astonishingly clever. It contains millions of neurons - as many as you would find in the brain of a cat - and is home to the microbiome, trillions of microbes that influence your mood, your immune system, and even your appetite.