 If you look at the classics, the most frequently cited articles in the scientific nutrition literature, the original glycemic index paper comes out at number 10, cited more than 1,000 times, and learning about fruit vegetables and cancer prevention was a hallmark. But hitting the top five, cited more than 2,000 times dietary modulation of the human microbiome, introducing the concept of prebiotics. Prebiotics are the food components that feed and nourish the good bacteria in our gut, like fiber and resistant starch. In general, eating high fiber plant foods is a good foundation for a prebiotic rich diet. Once upon a time, fiber was just thought of as just an undigested component of foods known only for bulking up stools and keeping our bowels regular. Then we discovered an array of receptors in the body in which fiber breakdown products fit in like a lock and key. We feed our good bacteria with fiber and they feed us right back, munching the fiber and creating short-chain fatty acids that get absorbed into our bloodstream and fit into these receptors that are expressed on immune cells and generally mediate a direct anti-inflammatory effect. So the reason for lower systemic inflammation in plant-based eaters may not just be due to the abundance of anti-inflammatory molecules in plant foods or the avoidance of pro-inflammatory molecules in animal foods, but from the production of anti-inflammatory molecules from scratch by our good gut bugs when we feed them fiber. Just to give you an idea how protective fiber-rich foods can be, those randomized to get advice to eat fiber-rich plant foods during radiation therapy for cancer didn't just experience reduced toxicity during the treatments, but even a full year later. Indeed, the benefits of fiber are supported by more than a century of research. Perspective studies show striking reductions in death from all causes put together, including total cancer deaths, total cardiovascular disease deaths and incidents, stroke incidents, and incidents of colorectal, breast, and esophageal cancer. And dose-response relationships suggest that the more the better in terms of protecting against heart attacks and stroke type 2 diabetes and cancer. So at a minimum, fiber intake should be no less than 25 to 29 grams per day, with additional benefits likely to crew with higher intakes. Yet the average American only consumes about 16 grams of fiber per day. We have co-evolved over millennia with gut bacteria to the point of reliance on our good gut bugs, a kind of symbiosis for fiber digestion in the production of short chain fatty acids and even certain vitamins. But we're not holding up our end of the bargain. We're supposed to be providing up to 100 or so grams of fiber a day, and we are barely passing along on measly 16 grams. The simplest solution, the simplest approach to remedy this lack of dietary fiber is to encourage consumption of whole food, plant-based nutrition.