Lactobacillus brevis

Lactobacillus brevis (sometimes identified as L. hilgardii) is a species of lactic acid bacteria. It can be found in many different environments and in fermented foods such as sauerkraut and pickles. It is also one of the most common causes of beer spoilage. Ingestion has been shown to improve human immune function, and it has been patented several times. 

L. brevis is one of the major Lactobacillus species found in tibicos grains (aka water kefir grains), and has been identified as the species responsible for the production of the polysaccharide (dextran) that forms the grains. Major metabolites of L. brevis include lactic acid and ethanol. Strains of L. brevis and L. hilgardii have been found to produce the biogenic amines tyramine and phenylethylamine.