Lactobacillus species

Lactobacillus species are a diverse group of Gram-positive, rod-shaped bacteria historically grouped under the genus *Lactobacillus*, which has recently been reclassified into 25 genera due to significant genetic diversity among its members. These bacteria are commonly found as part of the normal flora in human mucosal sites such as the gastrointestinal and vaginal tracts. They play key roles in food fermentation processes and have been widely used as probiotics due to their ability to promote gut health, inhibit pathogenic microbes through various mechanisms including competitive exclusion and production of lactic acid, modulate immune function—including enhancing antitumor immunity—and reduce inflammation. Therapeutically, they have demonstrated benefits across several conditions including prevention/treatment for antibiotic-associated diarrhea, bacterial vaginosis, eczema/atopic dermatitis in children with allergies, modulation during cancer therapy to reduce side effects like diarrhea/mucositis and potentially enhance response rates when combined with immune checkpoint inhibitors. However, "Lactobacillus species" refers collectively to many distinct organisms rather than a single molecular target such as an enzyme or receptor; thus it is not considered a therapeutic target per se but rather an administered agent composed itself by living cells that exert beneficial biological functions primarily through ecological interactions within host microbiomes rather than direct pharmacological targeting at the molecular level[1][3][5][7].

Other names

LactobacilliProbiotic lactobacilliLactic acid bacteria (informal, broader group)

For probiotic use—mechanisms include: - Restoration or maintenance of healthy microbiota balance - Competitive inhibition against pathogens - Production of antimicrobial compounds (e.g., lactic acid) - Modulation/regulation of host immune responses via cytokine signaling pathways[4][6]