Pterostilbene attenuates intestinal barrier damage and secondary liver oxidative stress in a murine model of <i>Clostridium difficile</i> infection by regulating the gut microbiota

<i>Clostridium difficile</i> infection (CDI) is a significant infectious disease with limited treatment options. Pterostilbene, an active compound found in blueberries, is known for its antioxidant and anti-inflammatory properties. This study investigated the effects of pterostilbene on intestinal barrier damage and secondary liver oxidative stress induced by CDI in mice. Pathological changes in the colon and liver, the levels of anti-inflammatory cytokines and antioxidants, and the expression of related genes were evaluated. Additionally, 16S rRNA sequencing and targeted metabolomics analyses of the gut microbiota and bile acids were conducted. Pterostilbene reduced the abundance of harmful bacteria such as <i>Enterococcus</i>, while increasing beneficial bacteria like <i>Lactobacillus</i>, thereby reshaping the gut microbiota and bile acid profile and reducing the accumulation of T-βMCA. This process activated intestinal FXR signaling, which alleviated colonic inflammation and reduced intestinal permeability. The reduction in intestinal permeability prevented the translocation of bacteria and bacterial toxins into the liver <i>via</i> the portal vein, thereby reducing liver inflammation and oxidative stress. Pterostilbene presented a promising strategy for maintaining intestinal health through the regulation of dysbiosis and bile acid disturbances caused by CDI. When integrated into the food system, pterostilbene has the potential to improve intestinal health, mitigate the risk of CDI associated with contaminated agricultural products, and enhance public health and food safety. Additionally, we identified that regulating the intestinal bile acid profile and the FXR receptor could serve as potential therapeutic targets for CDI, thereby facilitating the development of novel treatment options and dietary strategies.