Lactobacillus paracasei

Bacteria from the Lactobacillus paracasei species are typically rod shaped, gram-positive and facultatively heterofermentative, meaning that in addition to lactic acid, they can also produce other metabolites such as ethanol/acetic acid and carbon dioxide (CO2), depending on the conditions and what types of sugars are available to them.

L. paracasei is one of the species of lactic acid bacteria which is brilliantly able to adapt to different environments; this is why L. paracasei is found naturally in both the human and animal gut as well as being used as a starter culture in the food industry, commonly in dairy products. It is also a species which has received GRAS (generally recognised as safe) status and is used in probiotic supplements.

Historically there has been significant debate over the nomenclature of L. paracasei & L. casei species, with many strains being classed under either species in literature where they would in fact be more accurately labelled Lactobacillus paracasei subsp. paracasei, if we were to follow current guidelines.