We now know that we have to feed it to stay healthy. When we don’t feed it right (e.g., depriving it of dietary protein), those bacteria send blood-borne and neural signals that tell our brains to alter our behavior so that they can get the nutrition that they do need. Whether you like it or not, you’re eating for two—you’re in a symbiotic relationship with your gut, and if you hurt your gut, your gut will hurt you back.
