Microbiome-metabolomics insights into the feces of high-fat diet mice to reveal the anti-obesity effects of yak (Bos grunniens) bone collagen hydrolysates

In this study, a twelve-week intervention was conducted to investigate the anti-obesity effects of yak bone collagen hydrolysates (YBCH) on mice with a high-fat diet. The obesity-associated phenotypes of mice were detected and the feces of mice were jointly analyzed by 16S rRNA gene sequencing and untargeted metabolomics. Results indicated that supplementation with YBCH could ameliorate the obesity-associated phenotypes of mice, especially with the medium dose (MD) and high dose (HD) of YBCH. Compared with the high-fat diet control (HC) group, the ratio of Firmicutes and Bacteroidetes in the fecal microbiota of the low dose (LD), MD, and HD groups was separately decreased by 29.83 %, 70.85 %, and 75.70 %. Lachnospiraceae and Muribaculaceae were the key bacteria for the YBCH intervention, which might be attributed to their different substrate preferences. The joint analysis of the 16S rRNA gene sequencing and untargeted metabolomics suggested that the anti-obesity effects of YBCH might be achieved by up-regulating the arginine and proline metabolism and down-regulating the aromatic amino acids metabolism via the gut microbiota.