Protective effects of prophylactic Pediococcus pentosaceus LI05 administration in DSS-induced chronic colitis in mice

Inflammatory bowel disease (IBD) is a chronic, relapsing inflammatory disorder. Probiotics are being investigated as adjunctive treatments for IBD. The probiotic strain Pediococcus pentosaceus LI05 (PPLi) has shown protective effects against colonic inflammation, although its anti-inflammatory mechanisms remain incompletely understood. This study investigated the protective effects of PPLi and associated biological changes in a mouse model of dextran sulfate sodium (DSS)-induced chronic colitis. We assessed clinical manifestations, histological changes, serum cytokines, glucagon-like peptide-1 (GLP-1), microbial composition, and metabolic profiles. PPLi administration alleviated colitis symptoms, reduced intestinal fibrosis and permeability, decreased proinflammatory cytokine expression, and increased GLP-1 levels in colonic tissue and cultured L cells. These effects were accompanied by changes in microbial composition and metabolic profiles, including increased levels of short-chain fatty acids and L-glutamate. PPLi administration began before DSS exposure and continued throughout repeated DSS cycles. Under this regimen, PPLi administration was associated with attenuated colitis-related injury and changes in fecal microbial and metabolic profiles and colonic GLP-1 and cAMP levels. These findings support further investigation of the protective effects of PPLi under a prophylactic regimen.