Levilactobacillus brevis (L. brevis)

Levilactobacillus brevis (formerly Lactobacillus brevis) is a Gram-positive, rod-shaped, heterofermentative lactic acid bacterium that is a natural inhabitant of the human gastrointestinal and urogenital tracts and is common in fermented foods [1, 3]. It is primarily utilized as a probiotic therapeutic agent to support digestive and urogenital health, with clinical evidence supporting its use in managing irritable bowel syndrome (IBS), bacterial vaginosis, and oral health conditions like gum disease [2, 4, 7]. The bacterium exerts its beneficial effects by colonizing mucosal surfaces, producing antimicrobial metabolites such as lactic acid and hydrogen peroxide, and modulating the host immune system through surface layer proteins (Slps) that interact with pattern recognition receptors like DC-SIGN and Mincle [5, 6, 10]. Additionally, certain strains are recognized for their high production of gamma-aminobutyric acid (GABA), a neurotransmitter that may influence the gut-brain axis [8, 15, 19]. While generally considered safe, L. brevis populations can be depleted by concurrent antibiotic therapy, and the organism poses rare safety risks, such as endocarditis or sepsis, in severely immunocompromised individuals [1, 11]. It is categorized as a live biotherapeutic agent rather than a traditional molecular target or receptor [8, 12].

Other names

Lactobacillus brevisBetabacterium breve

As a probiotic, Levilactobacillus brevis exerts its effects through the competitive exclusion of pathogens, the production of antimicrobial metabolites (lactic acid, hydrogen peroxide), and the modulation of the host immune system via surface layer proteins (Slps) that interact with receptors such as DC-SIGN and Mincle [2, 6, 8]. It also produces gamma-aminobutyric acid (GABA), which can modulate the gut-brain axis [8, 15]. When the organism itself is a target of pharmacotherapy, its growth is inhibited by antibiotics through mechanisms such as the disruption of cell wall synthesis or the inhibition of protein translation [1, 11].