Lacticaseibacillus casei

Lacticaseibacillus casei is an organism that belongs to the largest genus in the family Lactobacillaceae, a lactic acid bacteria (LAB), that was previously classified as Lactobacillus casei-01. This bacteria has been identified as facultatively anaerobic or microaerophilic, acid-tolerant, non-spore-forming bacteria. The taxonomy of this group has been debated for several years because researchers struggled to differentiate between the strains of L. casei and L. paracasei. It has recently been accepted as a single species with five subspecies: L. casei subsp. rhamnosus, L. casei subsp. alactosus, L. casei subsp. casei, L. casei subsp. tolerans, and L. casei subsp. pseudoplantarum. The taxonomy of this genus was determined according to the phenotypic, physiological, and biochemical similarities. This species is a non-sporing, rod-shaped, gram positive microorganism that can be found within the reproductive and digestive tract of the human body. Since L. casei can survive in a variety of environmental habitats, it has and continues to be extensively studied by health scientists. Commercially, L. casei is used in fermenting dairy products and its application as a probiotic. The most common application of L. casei is industrial, specifically for dairy production. Lacticaseibacillus casei is typically the dominant species of nonstarter lactic acid bacteria (i.e. contaminant bacteria) present in ripening cheddar cheese, and, recently, the complete genome sequence of L. casei ATCC 334 has become available. L. casei is also the dominant species in naturally fermented Sicilian green olives. A commercial beverage containing L. casei strain Shirota has been shown to inhibit the in vivo growth of Helicobacter pylori, but when the same beverage was consumed by humans in a small trial, H. pylori colonization decreased only slightly, and the trend was not statistically significant. Some L. casei strains are considered to be probiotic, and may be effective in alleviation of gastrointestinal pathogenic bacterial diseases.