Feature Archive

The Truth About Probiotics and Your Gut

What Are Probiotics?

By Peter Jaret
WebMD Feature

Reviewed by Louise Chang, MD

Probiotics are microorganisms such as bacteria or yeast that are believed to improve health. They are available in supplements and foods. The idea of taking live bacteria or yeast may seem strange at first. After all, we take antibiotics and use antibacterial substances to fight bacteria. But our bodies naturally teem with such organisms.

The digestive system is home to more than 500 different bacterial species. They help keep intestinal linings healthy and assist in breaking down food. Beneficial organisms are also believed to help regulate healthy immune response.

How Do Probiotics Work?

Researchers believe that some digestive disorders result when the balance of friendly bacteria in the intestines becomes disturbed. This can happen after an infection or after taking antibiotics. Intestinal problems can also arise when the lining of the intestines is damaged. Introducing new beneficial organisms in the form of probiotics may help.

"Probiotics can improve intestinal function and maintain the integrity of the lining of the intestines," says Stefano Guandalini, MD, professor of pediatrics and gastroenterology at the University of Chicago Medical Center. These friendly bugs may also help fight off diarrhea-causing organisms.