We co-evolved a symbiosis with our good gut bacteria, but we aren’t holding up our end of the bargain. If you look at the classics—the most frequently cited articles in the scientific nutrition literature—the original glycemic index paper ranks tenth, cited more than a thousand times. Learning about fruits, vegetables, and cancer prevention comes in seventh. But hitting the top four, cited more than 2,000 times: “Dietary Modulation of the Human Colonic Microbiota: Introducing the Concept of Prebiotics.” As I discuss in my video How to Keep Your Microbiome Healthy with Prebiotic Foods, prebioti...