Hui Wang^{1, 2}, Kang Chen³, Mingxiu Long⁴, Jingwen Luo², Zhaojun Chen², Mei Wang², Xiaoai Chen², Shan Huang², Xin Zhang⁵, Tingyuan Ren⁵, Shuangxue Wu⁵, Jienan Lou⁵, Shuming Tan^{1, 5,}

Rosa roxburghii fruit pomace, rich in polyphenols, is an underutilized by-product in food processing. Polyphenols have been reported to have anti-diabetic properties. In this study, LC-MS metabolomics and 16S rRNA gene sequencing were used to study the effect of Rosa roxburghii fruit pomace polyphenols extract (RPPE) on plasma metabolites and gut microbiota in type 2 diabetic mice. RPPE was fed to diabetic mice at a daily dose of 400 mg/kg body weight for 8 weeks. Feeding RPPE decreased plasma glucose and proinflammatory cytokines and improved insulin sensitivity and plasma lipid profile. Oxidative stress biomarkers and inflammatory cytokines in colon were decreased by RPPE. For plasma metabolites, RPPE decreased p-cresol sulfate level and increased myristoleic acid, myristic acid, and palmitoleic acid levels, suggesting improved glucose and lipid metabolism as well as insulin resistance. Furthermore, RPPE upregulated abundance of beneficial microbes Lachnospiraceae and Erysipelotrichaceae and downregulate levels of detrimental microbes Faecalibaculum, Romboutsia, and Coriobacteriaceae. These results suggest that RPPE delays the development of type 2 diabetes via modulation of the inflammation, oxidative stress, plasma metabolites and gut microbiota.

type 2 diabetes, Rosa roxburghii fruit pomace, metabolomics