Fucoidan from Scytosiphon lomentaria protects against destruction of intestinal barrier, inflammation and lipid abnormality by modulating the gut microbiota in dietary fibers-deficient mice

Inadequate dietary fibers intake has been a threat for public health, and its adverse effect and regulatory mechanisms remain unclear. In this study, the protective effect of fucoidan from Scytosiphon lomentaria (SLF) on dietary fibers deficiency (FF)-induced change of physiological functions was analyzed in mice. SLF reduced weight gain and low-density lipoprotein cholesterol, increased high-density lipoprotein cholesterol, but had no effect on food intake and body fat mass in FF-treated mice. Lipidomics analysis showed that SLF modulated lipid metabolism, mainly involving glycerophospholipid and linolenic acid metabolism pathways. In addition, SLF protected against FF-induced colon damages, including the integrity of epithelial cell layer, loss of goblet cells, crypts and glycoproteins, and inflammatory cells infiltration. The underlying mechanisms can be associated with inhibition of oxidative stress, increase of tight junction proteins, and regulation of cytokines profile via nuclear factor kappa B pathway. On the other hand, SLF modulated FF-induced gut microbiota dysbiosis that had close relation with host physiological functions, e.g. increases in Akkermansia, Parabacteroides, Bacteroides and Alistipes. It indicates that SLF can be developed as a prebiotic agent to benefit host health through protecting intestinal barrier and regulating the gut microbiota.