Akkermansia muciniphila supplementation alters inflammatory profiles across diverse models of colitis

Inflammatory bowel disease (IBD) is characterized by chronic intestinal inflammation and is thought to result from interactions among the immune system, environmental factors, and the gut microbiota in genetically susceptible individuals. Akkermansia muciniphila, a commensal bacterium has been reported to be depleted in individuals with IBD, although its precise role in intestinal inflammation remains unclear. This study examined the effects of A. muciniphila across multiple models of colitis, including dextran sulphate sodium (DSS)-induced colitis, the Mucin-2 knockout (Muc2^-/-) model of spontaneous colitis, and Trichuris muris-mediated infectious colitis. In a DSS recovery model, treatment with pasteurized A. muciniphila reduced the severity of inflammation. However, when administered prior to DSS exposure, both live and pasteurized bacteria did not significantly reduce inflammatory markers, suggesting limited preventive effects. In T. muris-infected mice, supplementation with live A. muciniphila increased Th2 and anti-inflammatory cytokine responses, reduced parasite burden, and enhanced gene expression of the mucin Muc5ac. Additionally, both live and pasteurized A. muciniphila alleviated spontaneous colitis severity in Muc2^-/- mice, indicating that these protective effects occur independently of Muc2. These findings expand understanding of the role of A. muciniphila in intestinal inflammation and highlight its potential as a therapeutic target for inflammatory intestinal disorders such as IBD.