Abstract
Background/Objectives: 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 Polygonatum kingianum 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. Methods: 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. Results: 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 (Blautia, Odoribacter, Rikenellaceae_RC9_gut_group), restored SCFAs (acetate/propionate/butyrate), and modulated metabolic pathways (sphingolipid/linoleic acid metabolism). Conclusions: 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.