Over the past few years, the gut—and the trillions of bacteria inside it—has been getting a ton of buzz. Scientists are still learning exactly how and why gut bacteria play a role in our health, but they do know the gut’s bacterial makeup affects us far more than previously thought. Aside from improved digestion, having an abundance and a vast variety of good gut bacteria has been tied to reduced bowel inflammation, better regulated blood-sugar levels, lower cholesterol levels, and even improved mood. They’re also continuing to research the gut’s effects on everything from colon cancer to Alzheimer’s risk, and their findings are promising. Maybe that’s why sales of probiotic supplements have skyrocketed, and probiotic-fortified foods have become commonplace on supermarket shelves. These days, you can even send a stool sample to a team of scientists to get a personalized gut bacteria evaluation.
But here’s the thing most people don’t know: To reap these benefits, you also have to consume prebiotics, a type of dietary fiber on which probiotics feed. Here’s everything you need to know about this oft-overlooked nutrient.