Steam-Exploded Glucan from Hericium erinaceus Alleviates High-Fat Diet-Induced Obesity in Mice: Roles of Gut Microbiota Modulation and Lipid Metabolism Improvement

This study systematically investigated the therapeutic efficacy and mechanistic basis of a steam-exploded β-glucan fraction from Hericium erinaceus (SEG) in a murine model of high-fat diet (HFD)-induced obesity. Results indicated that administration of SEG significantly attenuated weight gain, alleviated dyslipidemia and hepatic steatosis, reduced systemic pro-inflammatory cytokine levels, and promoted white adipose tissue browning. 16S rRNA gene sequencing revealed that SEG effectively remodeled the gut microbiota (GM), characterized by a marked increase in the abundance of beneficial genera, including Eubacterium and Lachnospiraceae, along with a decrease in Erysipelotrichaceae, and elevated levels of beneficial metabolites such as acetate and butyrate. Furthermore, untargeted metabolomics analysis indicated that SEG intervention profoundly modulated host metabolism, particularly affecting pathways involved in tryptophan metabolism, glycerophospholipid metabolism, and bile acid secretion. Integrative multi-omics correlation analysis uncovered a potential relationship of “GM-metabolite-host”, providing a mechanistic basis for the observed weight loss effects. Further analysis showed that SEG intervention strengthened the positive correlation between microbially derived tryptophan metabolites and favorable host metabolic phenotypes such as elevated HDL-C, while attenuating the commonly observed negative correlation between secondary bile acids and key inflammatory markers.