Abstract BACKGROUND Apostichopus japonicus is a traditional medicinal and culinary species, with existing anti‐aging research primarily focusing on its bioactive peptides. In contrast, the anti‐aging potential of its major polysaccharide, fucoidan (Aj‐FUC), remains largely unexplored. Since the intestine is a central target in the aging process and the primary site for polysaccharide interaction, this study investigates the protective effects and underlying mechanisms of Aj‐FUC against d ‐galactose ( d ‐Gal)‐induced intestinal senescence in mice. RESULTS Aj‐FUC significantly improved intestinal function, including restoration of villus structure and colon length, as well as enhancement of motility, absorption, and digestive enzyme activity. Additionally, Aj‐FUC ameliorated the senescence‐associated secretory phenotype, reduced oxidative stress levels, and downregulated mRNA expression of P16 , P21 , and P53 , showing strong anti‐aging effects. Meanwhile, Aj‐FUC increased mRNA and protein levels of tight junction proteins, indicating improved intestinal barrier function. Further research revealed that Aj‐FUC activated the Wnt/β‐catenin pathway and promoted the proliferation of intestinal stem cells (ISCs). Moreover, Aj‐FUC remodeled the gut microbiota and enriched Lactobacillus , thereby promoting ISC growth. CONCLUSION Aj‐FUC mitigates intestinal aging primarily by modulating the gut microbiota and subsequently promoting ISC‐mediated epithelial renewal via the Wnt/β‐catenin pathway. These findings highlight the promise of Aj‐FUC as a marine‐based prebiotic functional food ingredient for improving intestinal health during aging. © 2026 Society of Chemical Industry.
Sun et al. (Thu,) studied this question.