Akermansia muciniphila shows promise as a next-generation probiotic, however, its beneficial regulatory effects on mice ulcerative colitis (UC) has not been extensively investigated. We used an Akkermansia muciniphila strain (AKK ONE) isolated from healthy human feces to study its effect on DSS-induced colitis in mice. Our results demonstrate that AKK ONE supplementation significantly improves food intake, weight, colon length, disease activity index (DAI) score, organ index, and tissue damage of colitis mice. AKK ONE notably improved intestinal barrier integrity by significantly enhancing expression of occludin and claudin-1. Additionally, AKK ONE reduced inflammation by down-regulating IL-1β, IL-6, and TNF-α, and up-regulating IL-10. In addition to reducing excessive inflammation, AKK ONE also increased the abundance of Akkermansia and decreased the abundance of Bacteroides. Furthermore, the AKK ONE intervention markedly increased SCFAs in cecal contents. AKK ONE may be a potential therapeutic agent for improving UC, based on the findings of this study.

The prevalence of stress-induced mental health disorders, such as anxiety and major depressive disorder, is increasing globally. Growing evidence suggests that gut microbiota plays a crucial role in cognitive function and emotional regulation via the gut-brain axis. As a result, probiotics have emerged as a promising dietary intervention for mental well-being, supported by their demonstrated ability to alleviate depressive behaviors in both clinical and preclinical settings—primarily through immune modulation, metabolic regulation, and microbial metabolite production. Although numerous studies have confirmed the potential of various probiotic strains to reduce depressive symptoms, only a limited number have been approved for commercial use to date. Key challenges remain, including variable clinical efficacy, instability during production and processing, and safety considerations, which must be addressed to facilitate their integration into functional foods. This comprehensive review discusses the mechanisms by which probiotics exert antidepressant effects, with a focus on host immunity, microbial metabolites, and neuroendocrine pathways. Furthermore, we offer critical insights into the current limitations and strategic directions for the application of probiotics in functional foods aimed at supporting mental health.