Blautia wexlerae ameliorates ulcerative colitis via metabolic remodeling of the gut microbiota.

This study aimed to explore regulatory strategies for ulcerative colitis (UC) and to elucidate their potential mechanisms. Blautia abundance and butyric acid concentration in the intestines of patients with UC are markedly lower compared to healthy volunteers. Supplementation with B. wexlerae HGD16 demonstrates superior therapeutic effects in alleviating UC relative to other Blautia species. Mechanistically, HGD16 inhibits the NF-κB pathway via indole-3-butyric acid (IBA)-macrophage-GPR40 axis, thereby improving intestinal immunity. Moreover, HGD16 and IBA interventions increase the abundance of Faecalibacterium butyricigenerans, which promotes butyrate production and enhances barrier function. Clinical cohort studies confirm that IBA content, B. wexlerae abundance, and colon GPR40 concentration in healthy volunteers are significantly higher than those in patients with UC, and are significantly negatively correlated with UC. These findings contribute to the clinical trials of B. wexlerae and to the theoretical research and development of UC dietary products.