CGA protects against experimental colitis by modulating host purine metabolism through the gut microbiota.

Objective: Alterations in the gut microbiota may contribute to the development of inflammatory bowel disease (IBD). Chlorogenic acid (CGA), a product of the esterification of caffeic acid and quinic acid, is one of the most abundant polyphenols in the human diet and has potential beneficial effects on gut function. However, the underlying mechanisms remain unclear. In this study, the pharmacological effects of CGA on colitis and the potential underlying mechanisms were investigated.

Methods: A mouse model of colitis was induced via the use of 4 % dextran sulfate sodium (DSS), and the mice were treated with 200 mg/kg CGA. Body weight, colon length, colon tissue pathology, and plasma and colon inflammatory cytokine levels were assessed. RNA sequencing was used to detect changes in gene expression in mouse colon tissues, and 16S rRNA sequencing was used to analyze the composition and structure of the gut microbiota. Fecal metabolomic analysis was performed, and fecal microbiota transplantation (FMT) was used to evaluate the contribution of the gut microbiota.

Results: CGA significantly alleviated DSS-induced colitis, alleviating intestinal mucosal barrier damage and gut microbiota dysbiosis. It significantly enriched bacteria that produce short-chain fatty acids (SCFAs). CGA inhibited the accumulation of purine metabolites derived from the microbiota and suppressed immune-related signaling cascades, exerting immunomodulatory effects. Furthermore, the gut microbiota of CGA-treated mice alleviated DSS-induced colitis through FMT.

Conclusion: CGA alleviates colitis in a gut microbiota-dependent manner, potentially providing a new strategy for the treatment of IBD.