Definition of Lactobacillus

Lactobacillus: A bacterium normally found in the mouth, intestinal tract, and vagina. Lactobacillus can also live in fermenting products, such as yogurt. Humans appear to have a symbiotic relationship with this bacteria: some types have become an important part of food digestion, although Lactobacillus can also contribute to cavities in the teeth if allowed to remain too long within the mouth.

Source: MedTerms™ Medical Dictionary
http://www.medterms.com/script/main/art.asp?articlekey=6203
Last Editorial Review: 3/19/2012