Understanding Probiotics: Types and Benefits of Good Bacteria

Good bacteria are also called friendly bacteria or probiotics. In Europe, scientists have developed products that contain beneficial strains of E. coli, but most good bacteria are one of two different types: lactobacilli or bifidobacteria.

• Bacteria under a microscope

Function

• More than 400 types of good bacteria live in the gastrointestinal tract. Good bacteria, such as lactobacilli or bifidobacteria, aid in digestion and "crowd out" intruders that cause infection.

Identification

• Lactobacilli, which breaks down diary products, reside primarily in the colon. Bifidobacteria reside primarily in the small intestine.

Theories/Speculation

• There might be a connection between intestinal bacteria and the immune system. Thus, if you beef up on good bacteria, you build up your body's natural defenses.

Expert Insight

• Dr. Scott Martin, physician assistant professor at the Medical College of Georgia, recommends sources of good bacteria to people on antibiotics. Antibiotics can wipe out lactobacilli or bifidobacteria in the gut, leaving the body susceptible to infections.

Sources

• Sources of good bacteria include yogurt, miso and sauerkraut. At specialty stores, also ask for kefir, which is a cultured milk drink, and tempeh, a fried cake made from soybeans.