Beneficial effects of flaxseed polysaccharides on metabolic syndrome via gut microbiota in high-fat diet fed mice

[Display omitted] •Flaxseed polysaccharide supplementation ameliorated the metabolic syndrome in HFD mice.•Flaxseed polysaccharide supplementation increased the proportion of Akkermansia and Bifidobacterium.•The improvement of lipid metabolism disorder was associated with the modulation of the gut microbiota. Flaxseed (Linum usitatissimum L.) is known as healthy food for its anti-obesity and lipid modulating properties. However, the effects of flaxseed polysaccharide (FSP) on metabolic syndrome (MetS) and gut microbiota are still poorly understood. Here, we investigated the effects of FSP on lipid metabolism and gut microbiota in high-fat-diet-fed mice. FSP effectively reduced the serum fasting glucose, total triglyceride and total cholesterol levels. FSP consumption adipose accumulation impacted the gut microbiome at different taxonomic levels by increasing the proportions of beneficial Akkermansia and Bifidobacterium and decreasing the disease or obesity associated Oscillospira and Odoribacteraceae. These changes were highly correlated with the regulation of expression levels of lipid metabolism involved genes in the liver. The restoration of total SCFAs, especially propionate and butyrate might be an important strategy for mitigating HFD induced metabolic disorders. These findings suggest that FSP may use as a prebiotic for preventing MetS by modulating the gut microbiota.