Beneficial effects of ginger on prevention of obesity through modulation of gut microbiota in mice

Purpose Recent evidence has demonstrated that the gut microbiota plays a critical role in the treatment of obesity and other metabolic dysfunctions. Ginger (Zingiber officinale Roscoe), one of the most commonly used spices and dietary supplements, has been shown to exert beneficial effects against obesity and related disorders. However, to date, the mechanisms linking these effects to the gut microbiota remain unclear. This study aims to investigate the relationship between the gut microbiota and the metabolic adaptations resulting from ginger supplementation in mice. Methods Four groups of mice were fed a normal chow diet (NCD) or a high-fat diet (HFD) with or without ginger supplementation for 16 weeks. Lipid profiles, proinflammatory cytokines, glucose tolerance, microbiota composition and short-chain fatty acid (SCFA) concentrations were analyzed at the end of the experiment. In addition, microbiota-depleted mice were transplanted with the fecal microbiota of mice fed a HFD or mice fed a HFD along with ginger supplementation. Glucose tolerance and microbiota composition were assessed after a 8-week fecal microbiota transplantation (FMT). Results We observed marked decreases in body weight, liver steatosis, and low-grade inflammation as well as amelioration of insulin resistance in the HFD-fed mice treated with ginger. Furthermore, ginger supplementation modulated the gut microbiota composition and increased species belonging to the Bifidobacterium genus and SCFA-producing bacteria (Alloprevotella and Allobaculum), along with increases in fecal SCFA concentrations. The FMT experiment showed anti-obesity and microbiota-modulating effects similar to those observed in the oral ginger-feeding experiment. Conclusions This study suggests that modulation of the gut microbiota as a result of ginger supplementation has a therapeutic effect on obesity in mice.