Green tea fermented by Ganoderma lucidum presented anti-obesity properties via enhanced thermogenesis in vitro and on C57BL/6J mice

High-fat diets contribute to obesity and metabolic disorders. Ganoderma lucidum is renowned for its abundant bioactive compounds and diverse pharmacological effects. Green tea fermented by G. lucidum (TFG) has been shown to enhance lipid-lowering activity in vitro significantly. Using UPLC-MS/MS and GC-MS/MS, we identified 78 active lipid-lowering compounds in TFG. We explored their potential targets and pathways through network pharmacology, validated by in vivo experiments. In a 4-week trial, 70 mice were randomly assigned to 7 groups: ND (normal diet), HFD (high-fat diet), PC-HFD (HFD with orlistat), NFT1 (HFD with 200 mg/kg/day non-fermented tea), NFT2 (HFD with 400 mg/kg/day NFT), TFG1 (HFD with 200 mg/kg/day TFG), and TFG2 (HFD with 400 mg/kg/day TFG). TFG treatment significantly reduced body weight, hepatic lipid droplets, and epididymal adipocyte size in mice compared to the HFD group. TFG also increased the abundance of lipid-lowering bacteria, such as Lactococcus and Lachnospirales. Liver transcriptomic and fecal metabolomic analyses revealed that TFG reduced triglyceride (TG), diglyceride (DG), monoglyceride (MG), and free fatty acid (FFA) levels and differentially regulated key genes (Dpf3, Atp5k, ND3) involved in the thermogenesis pathway. RT-PCR confirmed that TFG upregulated the mRNA expressions of AMPK, UCP1, PGC1α, and PPARγ in dorsal fat. In conclusion, TFG enhances thermogenesis via the AMPK-PGC1α pathway and increases the abundance of lipid-lowering bacteria, thereby reducing fat accumulation in mice. These findings offer insights into TFG's anti-obesity mechanisms, providing a scientific basis for developing new weight loss methods or products.