Fucoidan isolated from Ascophyllum nodosum alleviates gut microbiota dysbiosis and colonic inflammation in antibiotic-treated mice

Antibiotic treatment, as an important therapeutic intervention, can cause damage to the host microbiome and the intestinal mucosal barrier. In order to find a way to alleviate the side effects of antibiotics, the present study investigated the effects of fucoidan (ANP) isolated fromAscophyllum nodosumon gut microbiota dysbiosis and colonic inflammation induced by ciprofloxacin-metronidazole (CiMe) in C57BL/6J mice. Our results showed that dietary ANP prevented colon shortening, alleviated the colonic tissue damages, and partially reversed the alteration of gut microbiota by increasing the abundance of potentially beneficial bacteria,e.g.,Ruminococcaceae_UCG_014andAkkermansiaand decreasing the abundance of harmful bacteria,e.g.,ProteusandEnterococcus. ANP also suppressed the overproduction of TNF-alpha, IL-1 beta, and IL-6 and promoted the expression of IL-10. In addition, ANP reversed the decreased production of short-chain fatty acids in CiMe-treated mice. Furthermore, correlation analysis indicated the presence of critical gut microbiota, which played important roles in reducing the inflammation-related indices. Thus, the present study suggests that fucoidan isolated fromAscophyllum nodosumis effective in providing protection against the negative effects of antibiotics on gut microbiota and colonic health.