Fucoidan from Saccharina japonica alleviates OVA-induced allergy in mice: A role for the AMPK/SIRT1/FOXO1 pathway in enhancing intestinal barrier function

Fucoidan is a sulfated polysaccharide derived from brown algae ( Saccharina japonica ), and exhibits immunomodulatory properties. Emerging evidence suggests a strong correlation between the development of food allergy and intestinal dysfunction. The present study aimed to investigate the potential anti-food allergy activity of fucoidan and to elucidate its mechanism at the intestinal barrier function. The ovalbumin (OVA)-induced allergy mouse model was established, exhibiting increased OVA-specific IgE, histamine, Th2 inflammatory response, and intestinal damage. Oral administration of fucoidan markedly alleviated allergic symptoms by inhibiting mast cell activation and modulating intestinal immune responses. Furthermore, fucoidan significantly ameliorated intestinal immunological dysregulation, maintained barrier integrity, modulated gut microbiota composition, and enhanced short-chain fatty acid (SCFA) production. Mechanistically, the protective effects of fucoidan were closely associated with activation of the AMPK/SIRT1/FOXO1 pathway, which correlated with improved intestinal barrier function. Collectively, these results demonstrate that fucoidan may protect against food allergy by enhancing intestinal barrier function, highlighting the potential of natural biological substances in addressing food allergy.