Sarcodon aspratus polysaccharides ameliorated obesity-induced metabolic disorders and modulated gut microbiota dysbiosis in mice fed a high-fat diet

Sarcodon aspratus is a popular edible fungus that has commonly been used as a functional food in China and other Asian countries. This study is conducted to examine the potential health benefits of Sarcodon aspratus polysaccharides (SATPs), on obesity and related metabolism disorders. C57BL/6J mice were fed with a high-fat diet (HFD) and supplemented with SATPs (100-400 mg kg(-1)) for 14 weeks. The results indicated that SATP treatment markedly reduced HFD-induced body weight gain and fat accumulation in a dose-dependent manner. SATPs could improve lipid homeostasis and glucose tolerance in HFD-fed mice. Furthermore, SATP intervention significantly attenuated hepatic steatosis, liver oxidative stress and inflammation. Additionally, we detected the macrophage and mRNA levels of lipogenesis markers in epididymal adipose tissues, and the results revealed that SATPs exerted inhibitory effects on the activation of immune cells and adipocyte differentiation in adipose tissues. High-throughput pyrosequencing of 16S rRNA suggested that SATP intervention was able to down-regulate the Firmicutes-to-Bacteroidetes ratio, and also increase the relative abundance of Lactobacillus, Bacteroides and Akkermansia in mice with HFD challenge. Taken together, SATPs showed ameliorative effects on hepatic steatosis, inflammation and adipocyte differentiation in HFD-fed mice. Notably, SATPs could modulate HFD-induced dysbiosis of gut microbiota. Thus, they might be a potential health supplement or prebiotic in the prevention of obesity and related metabolic disorders.