Your intestinal tract is home to 100 trillion probiotic bacteria that help you stay healthy. If you want those good bugs to keep doing their health-promoting tasks, you have to feed them the right stuff.

While you may have your favorite foods that you crave every day, so do the beneficial bacteria in your intestines. Their taste can be summed up in one word: fiber. Fibrous foods help these little bugs protect us against type 2 diabetes, weight gain, inflammatory bowel disease, colon cancer and autoimmune disorders such as rheumatoid arthritis.

“Unfortunately, people eat only about half of the 30 to 35 grams of daily fiber that is recommended. To achieve… health benefits, consumers should read nutrition labels and choose foods that have high fiber content,” says researcher Kelly Swanson of the University of Illinois at Urbana-Champaign.

Swanson’s research shows that adding more dietary fiber to your diet may improve your well-being as well as the well-being of the bugs in your gut.

“For example, one type of bacteria that thrived as a result of the types of fiber fed in [our] study is inherently anti-inflammatory, and their growth could be stimulated by using prebiotics, foods that promote the bacteria’s growth, or probiotics, foods that contain the live microorganism,” he says.