Lactobacillus plantarum is a widespread member of the genus Lactobacillus, commonly found in many fermented food products as well as anaerobic plant matter. It is also present in saliva (from which it was first isolated). It has the ability to liquefy gelatin. L. plantarum has one of the largest genomes known among the lactic acid bacteria and is a very flexible and versatile species.

L. plantarum is commonly found in many fermented food products including sauerkraut, pickles, brined olives, Korean kimchi, Nigerian ogi, sourdough and other fermented plant material, and also some cheeses fermented sausages and stockfish. The high levels of this organism in food also makes it an ideal candidate for the development of probiotics. In Juana Frias et al.(2008)'s study, L. plantarum has been applied to reduce the allergenicity of soy flour. The result showed that, compared to other microbes, L. plantarum-fermented soy flour showed the highest reduction in IgE immunoreactivity (96–99%), depending upon the sensitivity of the plasma used.

The ability of L. plantarum to survive in the human gastro-intestinal tract makes it a possible in vivo delivery vehicle for therapeutic compounds or proteins.