Black ginseng extract attenuates high-fat diet-induced obesity by stimulating ileal TGR5 activation and modulating gut microbiota

Black ginseng as the functional food, has been used to improve obesity and insulin resistance. However, the underlying mechanism remains unclear. We found that Black ginseng extract (BGS) significantly ameliorated diet-induced obesity and insulin resistance in mice. The components eluted by 70% and 95% ethanol from BGS by using polystyrene resin (BGS/70) had superior anti-obesity effects when compared with other fractions. It significantly decreased the abundance of bile salt hydrolase (BSH)-producing genera and increased serum taurine-bound bile acids in obese mice. BGS/70 administration-related metabolic improvements in obese mice was lost in TGR5 gut-specific knockout mice and antibiotic mixture (ABX)-cleared enterobacteria mice. Fecal microbiota transplantation (FMT) experiments demonstrated that the anti-obesity effects of BGS/70 were mediated by gut flora. Taken together, our results suggest that BGS can treat obesity via gut microbiota and the activation of TGR5. Thus, BGS may be a promising therapy for obesity.