Fucoidan is a kind of polysaccharide with antitumor and antioxidant properties, which is mainly isolated from brown algae. Although there are many reports about the prebiotic effects of polysaccharides on hosts, there are few reports about the effects of fucoidan on blood biochemical indexes, intestinal microbiome, and metabolic function on healthy hosts. We applied 16S rRNA gene amplicon sequencing and LC-MS/MS metabolomics to evaluate the changes in the gut microbiome and metabolite profiles of fucoidan treatment in mice over 10 weeks. Fucoidan treatment modulated lipid metabolism, including significantly decreasing serum triglyceride level in healthy mice. Fucoidan also significantly inhibited serum lipopolysaccharide-binding protein (LBP) concentration, a biomarker of endotoxemia. Correlation analysis further showed that Lactobacillus animalis populations that were enriched by fucoidan demonstrated significantly negative correlations with serum triglyceride level. The abundance of Lactobacillus gasseri and Lactobacillus reuteri, increased by fucoidan supplementation, demonstrated significantly negative correlation with lipopolysaccharide-binding protein levels. Lactobacillus gasseri also demonstrated significantly positive correlations with three tryptophan-related metabolites, including indoleacrylic acid, 3-indoleacrylic acid, and 5-hydroxytryptamine, which were all increased by fucoidan administration. Combined with the previous evidence, the results indicate that fucoidan exerts prebiotic effects, such as lipid metabolism suppression and metabolic endotoxemia suppression, by modulating the abundance of gut microbiota, such as Lactobacillus animalis, Lactobacillus gasseri, and Lactobacillus reuteri, as well as microbiota-dependent metabolites, such as tryptophan-related metabolites.
Alpha-Linolenic Acid-Enriched Diacylglycerol Oil Suppresses the Postprandial Serum Triglyceride Level—A Randomized, Double-Blind, Placebo-Controlled, Crossover Study