Liubao Tea Extract Attenuates High-Fat Diet and Streptozotocin-Induced Type 2 Diabetes in Mice by Remodeling Hepatic Metabolism and Gut Microbiota

Background: Type 2 diabetes (T2D) has become a serious global public health concern. Liubao tea (LBT) has demonstrated beneficial effects on gut microbiota and glucose-lipid metabolism, holding promising therapeutic potential for T2D; however, its underlying mechanisms remain unclear. This study aims to elucidate the potential mechanisms of Liubao tea extract (LBTE) against T2D. Methods: LC-MS technology was used to identify the chemical components of LBTE and combined with network pharmacology and molecular docking to screen its potential active ingredients and targets for improving T2D. Therapeutic efficacy was assessed in high-fat diet/streptozotocin (HFD/STZ)-induced diabetic mice via serum biochemical analyses and histopathological examinations. Serum metabolomics, 16S rRNA sequencing, quantification of short-chain fatty acids (SCFAs), quantitative real-time PCR (qPCR), and antibiotic-treated pseudo-germ-free models were employed to elucidate the underlying mechanisms. Results: LBTE effectively reduced blood glucose levels and improved lipid metabolism, primarily by promoting hepatic glycogen synthesis and suppressing glycerophospholipid synthesis. LBTE also alleviated hepatic inflammation by modulating inflammatory cytokine expression. Additionally, LBTE reshaped the gut microbiota profiles by decreasing harmful bacteria and increasing SCFA-producing bacteria, resulting in elevated fecal SCFAs. SCFAs contributed to improving hepatic metabolism and inflammation, enhancing intestinal barrier function. Notably, these effects were abolished by antibiotic-induced microbiota depletion, confirming the microbiota-dependent mechanism of LBTE. Quercetin, luteolin, genistein, and kaempferol were considered as potential active ingredients contributing to the antidiabetic effects of LBTE. Conclusions: These findings provide novel perspectives on the viability of LBTE as a complementary strategy for T2D prevention and management.