Phellinus linteus polysaccharides alleviate DSS-induced colitis in mice by restoring gut microbiota homeostasis, preserving intestinal barrier integrity, and attenuating JAK2/STAT3-associated inflammatory signaling

From the paper

Abstract

Abstract Background & aims Phellinus linteus polysaccharides (PLP), bioactive polysaccharides derived from the traditional medicinal fungus Phellinus linteus, have shown potential anti-inflammatory activity. However, their protective effects against ulcerative colitis and the related mechanisms remain incompletely understood. This study aimed to evaluate the effects of PLP on DSS-induced colitis in mice and to investigate the potential involvement of gut microbiota, intestinal barrier function, and inflammation-related signaling pathways. Methods A colitis model was established in male C57BL/6 mice by administration of 2.5% DSS in drinking water for 7 days. Mice were then treated with PLP at doses of 10, 20, or 40 mg/kg, 5-aminosalicylic acid as a positive control, or phosphate-buffered saline for 2 weeks. Disease severity, intestinal barrier integrity, inflammatory responses, gut microbiota composition, and related signaling pathways were evaluated. Fecal microbiota transplantation was further performed to assess the contribution of gut microbiota to the protective effects of PLP. Results PLP, particularly at 40 mg/kg, alleviated DSS-induced colitis symptoms and intestinal injury, as indicated by reduced colon shortening and improved intestinal mucosal barrier integrity. PLP treatment also reduced inflammatory responses and was associated with decreased activation of Jak2/STAT3 and NF-κB-p65 signaling pathways. In addition, PLP partially restored DSS-induced gut microbiota dysbiosis. Fecal microbiota transplantation further suggested that the protective effects of PLP are at least partly microbiota-dependent. Conclusions PLP alleviates DSS-induced colitis in mice, potentially by improving gut microbiota homeostasis, preserving intestinal barrier integrity, and suppressing inflammation-associated signaling pathways. These findings support PLP as a potential dietary or natural product-based intervention for colitis, although further mechanistic validation is required.