Alleviation effect of Potentilla anserina polysaccharides on intestinal barrier dysfunction and its underlying mechanism.

The present study aimed to analyze the physicochemical characteristics of Potentilla anserina polysaccharides (PAP) and investigate their alleviation effect on cyclophosphamide (CTX)-induced intestinal barrier dysfunction in mice. PAP was found to contain a total sugar content of 65.07 ± 1.42%, uronic acid content of 33.54 ± 1.15%, and protein content of 1.59 ± 0.19%. In the CTX-induced immunosuppressed mouse model, administration of PAP at doses of 40, 80, and 160 mg/kg significantly attenuated the trend of body weight loss and effectively elevated serum levels of cytokines (IFN-γ, TNF-α, IL-17) and immunoglobulins (IgA, IgM); however, it had no significant effect on IL-22 levels or on the thymus and spleen indices. Moreover, PAP ameliorated intestinal immune injury by enhancing the synthesis of tight junction proteins, increasing the proportion of CD4+ and CD8+ T cells, and upregulating the expression of key intestinal T cell transcription factors and cytokines. Critically, PAP administration significantly increased short-chain fatty acids (SCFAs) levels and alleviated gut microbiota dysbiosis through dual modulation: promoting the abundance of beneficial bacteria (including Ligilactobacillus, Monoglobus, Bacteroides, the Eubacterium xylanophilum group, and the Eubacterium siraeum group) while suppressing pathogenic genera (such as Colidextribacter, Clostridium, Oscillibacter, and Lachnoclostridium). Functional prediction analysis further revealed that PAP contributes to host health by modulating key metabolic pathways, including inorganic ion transport and metabolism, styrene degradation, and amino acid metabolism. This study demonstrated that PAP exerted intestinal protective effects by remodeling the gut microbiota structure, promoting short-chain fatty acid (SCFA) production, and thereby modulating local immune function in the ileum. This modulation is specifically evidenced by the regulation of T cell subset differentiation and transcription factor expression, which ultimately leads to the restoration of the intestinal epithelial tight junction barrier. These findings indicate that PAP holds significant potential as a functional food ingredient or therapeutic agent for the management of intestinal barrier dysfunction.