Fucoidan Alleviates Colitis and Metabolic Disorder by Protecting the Intestinal Barrier, Suppressing the MAPK/NF-κB Pathways, and Regulating the Gut Microbiota

Abstract

Scytosiphon lomentaria is widely consumed in China’s coastal regions due to its various beneficial effects, although its exact mechanism has yet to be fully elucidated. This study demonstrated that S. lomentaria fucoidan (SLF) alleviated colitis symptoms in mice, as evidenced by a reduction in colonic tissue damage and an increase in colon length and weight gain. Metabolomics analysis indicated that SLF improved abnormal serum metabolites profile associated with colitis, affecting metabolic pathways related to amino acid, lipid, and tricarboxylic acid cycle. SLF alleviated colonic inflammation through inhibiting the activation of MAPK/NF-κB pathways and attenuating oxidative stress. The protective effect of SLF in maintaining the gut barrier integrity is supported by the preservation of goblet cells and glycoproteins and increased expression of ZO-1 and claudin. The underlying mechanism can be associated with the improvement of the gut microbiota, including an increase in microbiota diversity and richness and the levels of beneficial bacteria and metabolites (e.g., Muribaculum, Parabacteroides, and short-chain fatty acids) and a reduction in harmful bacteria. This study implies that SLF holds great potential to be used as a prebiotic agent to enhance human and gut health.