Obesity is a
metabolic disease and causes significant changes in host and gut microbial metabolite levels. However, little research has been done on the relationship between host and gut microbial metabolites. Thus, this study investigated the connection of the chemicals, based on the different effects of two Inonotus obliquus extracts on high-fat-diet-induced mice and their mechanisms. In this study, C57BL6/J mice fed with a high-fat diet were given I. obliquus
ethanol extract (IOE) and
polysaccharide (IOP). 1H NMR-based metabolomics,
16S rRNA sequencing, and real-time reverse transcription polymerase chain reaction (RT-PCR) were used to detect metabolites, cecal microbes, and expressions of genes in liver. IOE and IOP effectively improved the
obesity of mice, including the adjustment of
body weight gain, energy intake, energy efficiency, liver
glucose metabolism and
triglyceride metabolism,
tricarboxylic acid (TCA) cycle, and degradation of three major nutrients (
carbohydrate,
lipid, and
protein). IOE significantly increased cecal
propionate based on Bacteroides and Akkermansia, thereby inhibiting energy intake and fat accumulation in mice. IOP remarkably improved the level of cecal
butyrate by Lactobacillus and the Bacteroidales S24-7 group, resulting in increased energy consumption, and fat degradation by regulating the TCA cycle of the host. Two extracts containing different bioactive substances of I. obliquus improved
obesity in mice through different effects on production of cecal microbial metabolites. Moreover, cecal
butyrate (not
propionate) was connected with chemicals of mice, including four metabolites of the TCA cycle and other metabolism-related chemicals.