Lactobacillus rhamnosus

Lactobacillus rhamnosus is a gram-positive, lactic acid bacteria that is commonly found in the human gastrointestinal tract and mouth. Lactobacillus rhamnosus is one of the most common types of probiotics and can be found in fermented foods, yogurt and dietary supplements. It is one of many species of bacteria in the family Lactobacillaceae (or "rod shaped" bacteria). 

Like other probiotics, Lactobacillus rhamnosus is considered a "good" bacteria and important for a healthy gut flora. Lactobacillus rhamnosus helps fight off "bad" bacteria that might cause diseases, such as irritable bowel syndrome, hence taken as a supplement to aid digestive health.

Outside of the gut, Lactobacillus rhamnosus is also used to stave off an overgrowth of "bad" bacteria in the vagina such as Helicobacter pylori which may cause infections.

For nutritional values, refer to the Codex entry for Probiotic.