Lacticaseibacillus casei W56 (L. casei W56)

Lacticaseibacillus casei W56 (formerly known as Lactobacillus casei W56) is a specific probiotic bacterial strain widely recognized for its role in maintaining gastrointestinal health and modulating the gut-brain axis [1, 3]. As a member of the lactic acid bacteria group, it functions by reinforcing the intestinal epithelial barrier, thereby reducing intestinal hyperpermeability, which is often associated with systemic inflammation and various chronic conditions [18, 22]. The strain is a key component of multi-species probiotic formulations like Ecologic Barrier, which have been studied for their potential to alleviate symptoms of depression, anxiety, and irritable bowel syndrome [20, 21]. L. casei W56 interacts with the host through immunomodulatory pathways, promoting the production of anti-inflammatory cytokines and enhancing the competitive exclusion of enteric pathogens [13, 17]. While generally considered safe for the general population, clinical caution is advised for severely immunocompromised patients due to the rare risk of opportunistic infections such as bacteremia [11, 19]. Its therapeutic utility is primarily explored in the context of functional gastrointestinal disorders and psychiatric conditions linked to microbiota dysbiosis [35].

Other names

Lactobacillus casei W56Lactobacillus casei strain W56L. casei W56

Lacticaseibacillus casei W56 strengthens the intestinal epithelial barrier by modulating tight junction proteins such as ZO-1 and occludin [18, 22]. It produces antimicrobial substances like bacteriocins and organic acids (e.g., lactic acid) to inhibit the growth of pathogens [14, 17]. Additionally, it modulates the host immune system by inducing regulatory T cells and balancing pro- and anti-inflammatory cytokines, and competes with pathogenic bacteria for adhesion sites on the intestinal mucosa [13, 15, 17].