Cordyceps militaris Polysaccharide Restores Gut Microbiome to Ameliorate DSS-Induced Colitis via the PPARy/ NF-kB Pathway

Purpose: We aimed to investigate the protective effect of Cordyceps militaris polysaccharide (CMP) against dextran sulfate sodium (DSS)-induced inflammatory bowel disease (IBD) in mice and to elucidate its underlying mechanisms, focusing on the regulation of the PPARy-NF-kB signaling axis, repair of the intestinal barrier, and remodeling of the gut microbiota.Methods: To establish the DSS-induced colitis model, six-week-old male ICR mice were employed. The therapeutic efficacy of CMP was evaluated by assessing the disease activity index (DAI), colon length, histopathological sections (H&E staining), and serum levels of inflammatory cytokines (ELISA). We evaluated the protein abundance of essential tight junction components, namely ZO-1, Occludin, and Claudin-1, through both immunofluorescence staining and qPCR. Gut microbiota structure was analyzed using 16S rRNA sequencing. Both in vivo (mouse colon tissue) and in vitro experiments (using LPS-induced Caco-2 cells), combined with transcriptome sequencing (RNA-seq), Western blot, and qPCR, were conducted to analyze the expression changes of key molecules in the PPARy-NF-kB signaling pathway.