Dendrobium officinale Polysaccharide Relieves the DSS-Induced Chronic Colitis in C57BL/6J Mice and Regulates Colonic Microflora Structure.

Background/

Objectives

Chronic colitis presents a growing global health burden with rising incidence. This study investigated the ameliorative effect of Dendrobium officinale polysaccharide (DOP) against dextran sulfate sodium (DSS)-induced chronic colitis in mice, specifically examining its dual modulation of gut microbiota and metabolic pathways.

Methods

DOP was extracted and purified from Dendrobium officinale stems and leaves. A chronic colitis model was established in male C57BL/6J mice via DSS induction. Eighty-four mice were randomized into seven groups: control, model, low/high-dose leaf-DOP, low/high-dose stem-DOP, and sulfasalazine positive control. We assessed body weight, disease activity index (DAI), colon length, splenic/thymic indices, inflammatory cytokines, and histopathology (Hematoxylin and Eosin/Alcian blue staining), with tight junction protein and tumor necrosis factor-alpha (TNF-α) expression quantified via immunofluorescence. 16S rRNA sequencing and untargeted metabolomics evaluated microbial and metabolic shifts.

Results

DOP significantly attenuated colitis severity, restored colon histoarchitecture, elevated goblet cell counts, upregulated zonula occludens-1 (ZO-1) and occludin expression, and suppressed TNF-α. Crucially, DOP remodeled dysbiosis by enriching beneficial taxa (e.g., Candidatus_Saccharimonas, Lachnoclostridium) while reducing pathogens (Mucispirillum). Metabolomics further elucidated DOP-mediated regulation of purine and nicotinate/nicotinamide metabolism-pathways mechanistically linked to its anti-inflammatory and barrier-repair effects.

Conclusions

DOP effectively alleviates symptoms of DSS-induced chronic colitis in mice, protects intestinal barrier integrity, and achieves therapeutic potential through simultaneous regulation of the gut microbiome and metabolome.