High-fat diet (HFD) induced
obesity and its associated conditions, such as hepatic steatosis and
steatohepatitis, are major health concerns worldwide. Previous studies have reported the excellent efficiency of Fuzhuan brick
tea (FBT) in attenuating HFD-induced
obesity and metabolic disorders. In this study, we investigated the effects of FBT on hepatic steatosis and simple
steatohepatitis in HFD-induced obese mice, as well as the metabolic function of the gut microbiome using metagenomics and metabolomics. The results showed that FBT ameliorated
dyslipidemia, hepatic steatosis and
steatohepatitis in HFD-induced obese mice by normalizing the gut microbiota structure and
tryptophan metabolism. FBT increased the cecal abundance of
aryl hydrocarbon receptor (AhR)-
ligand producing bacteria such as Lactobacillus_reuteri and Lactobacillus_johnsonii, at the expense of AhR-
ligand consuming bacteria, such as Faecalibaculum_rodentium and Escherichia_coli, and elevated the cecal contents of AhR-
ligands such as IAA, IPA, and KYNA. Furthermore, FBT regulated the expressions of AhR and its targeted lipometabolic genes such as Pemt, Fasn, and
SREBP-1c, as well as other inflammatory genes including TNF-α,
IL-6, and IL-1β in the liver of mice. Overall, these findings highlight the beneficial effects of FBT on
obesity-related hepatic steatosis and
steatohepatitis via microbiota-derived AhR signaling.