Fucoidan dose-dependently alleviated hyperuricemia and modulated gut microbiota in mice

The global incidence of hyperuricemia (HUA) is gradually increasing, and HUA poses a severe threat to human health. Between 25% and 50% of HUA patients are not effectively treated with current clinical medications due to drug contraindications or severe adverse reactions. Therefore, novel safe and effective uric acid-lowering products are needed. Fucoidan is a naturally derived polysaccharide containing sulfate groups exclusively found in brown algae. Although there are reports on the anti-HUA effects of fucoidan, the simultaneous regulation of gut microbiota by anti-HUA still needs to be fully understood. In this study, potassium oxonate (PO) and hypoxanthine-induced HUA model mice were treated with 100, 200 and 400 mg/kg fucoidan (from Laminaria japonica) for 14 days. The levels associated with HUA were quantified using assay kits to assess fucoidan intervention. 16S rRNA gene sequencing was used to analyze the effects of fucoidan in mice with HUA. The results showed that fucoidan reduced serum uric acid and urea nitrogen levels in a dose-dependent manner, and serum creatinine levels in the 200 and 400 mg/kg fucoidan groups were similar to those in the control group. It decreased the expression of uric acid metabolic protein levels of xanthine oxidase (XOD), adenosine deaminase (ADA), and glucose transporter (GLUT9) and increased ATP binding cassette subfamily G member 2 (ABCG2) protein expression. 16S rRNA gene sequencing revealed that the richness (Chao and Ace indices) and diversity (Shannon and Simpson indices) of the gut microbiota in model mice decreased, whereas supplementation with fucoidan alleviated gut microbiota dysbiosis in HUA model mice, leading to a gradual approach of α-diversity and β-diversity towards the control mice. Additionally, fucoidan supplementation significantly increased the abundance of beneficial bacteria, which are negatively correlated with the HUA-associated phenotypes, reassuring the positive effects of fucoidan on gut health. This study proposed that fucoidan can be considered a potential candidate for preventing and treating HUA.