Integrative Multi-Omics Reveals the Anti-Colitis Mechanisms of Collett & Hemsl Polysaccharides in a Mouse DSS Model.

: Ulcerative colitis (UC) incidence has risen alarmingly worldwide, posing significant clinical challenges due to limitations of therapeutic efficacy and side effects of current drugs. While polysaccharides (PKPs) exhibit anti-inflammatory and antioxidant properties, their anti-colitis potential remains unexplored. This study aimed to validate the protective effects of PKPs against dextran sulfate sodium (DSS)-induced colitis and elucidate its mechanisms. : Acute UC was induced in C57BL/6J mice by 3% DSS. PKPs (125 mg/kg) were administered via gavage for 10 days. Integrated approaches included histopathology, tight junction protein (ZO-1/Occludin/Claudin-1) immunohistochemistry, inflammatory/oxidative markers (ELISA), Nrf2 pathway proteins (Western blot), 16S rRNA gut microbiota sequencing, fecal untargeted metabolomics (UHPLC-MS), short-chain fatty acids (SCFAs) analysis and combined analysis. : PKPs significantly alleviated colitis phenotypes: reduced weight loss, lowered disease activity index (DAI), and attenuated colon shortening. They restored intestinal barrier integrity by upregulating tight junction proteins and reducing plasma Diamine Oxidase (DAO)/D-lactate (D-Lac)/Endotoxin (ET). PKPs suppressed pro-inflammatory cytokines (TNF-α/IL-1β/IL-6) while elevating IL-10, activated the Nrf2/HO-1/NQO1 antioxidant pathway, and reduced oxidative stress (MDA decreased, SOD/GSH increased). Multi-omics revealed PKPs enriched beneficial bacteria (, , ), restored SCFAs (acetate/propionate/butyrate), and modulated metabolic pathways (sphingolipid/linoleic acid metabolism). : PKPs ameliorate DSS-induced colitis through multi-target mechanisms: (1) preserving intestinal barrier function, (2) suppressing inflammation and oxidative stress via Nrf2 activation, (3) restoring gut microbiota balance and SCFA production, and (4) regulating host-microbiota metabolic interactions. These findings support PKPs as a promising dietary supplement for UC management.