Lactobacillus

About Lactobacillus

Lactobacillus is a genus of Gram positive, rod shaped, non spore forming bacteria that ferment carbohydrates mainly into lactic acid. Such lactic acid bacteria have long been used to make yogurt, cheese, sourdough, sauerkraut, kimchi, and kefir. In 1905 the Bulgarian physician Stamen Grigorov identified the yogurt organism now called Lactobacillus delbrueckii subspecies bulgaricus, and the ideas of Elie Metchnikoff about fermented milk helped launch the concept of probiotics. In 2020 the genus was reclassified into 25 genera, so familiar species now carry names such as Lacticaseibacillus rhamnosus, Limosilactobacillus reuteri, and Lactiplantibacillus plantarum, though Lactobacillus remains in common use. Lactobacilli inhabit the human gut and mouth and dominate the healthy vaginal microbiota, where lactic acid keeps the environment acidic. Probiotic strains have been studied for infectious and antibiotic associated diarrhea, infant colic, and vaginal health, with strain specific effects and evidence that varies by condition.