OBJECTIVE: Coptis chinensis (Huanglian in Chinese, HL) is commonly utilized in clinical settings to counteract dyslipidemia in patients with hot syndrome. Its lipid-reducing efficacy has been consistently demonstrated in high-fat diet (HFD)-induced hyperlipidemic animal models. However, whether HL's efficacy differs in HFD-fed animals with hot or cold syndromes remains unclear. This study aims to discern the variations in the anti-hyperlipidemic effects of HL in HFD-fed mice with hot or cold syndromes. METHODS: HFD-induced C57BL/6 mice were subjected to cold or hot syndrome via two weeks of ice water (0 °C) and levothyroxine sodium (240 µg/kg) treatment, respectively. Then, an aqueous extract of HL was administered to the mice via oral gavage over the following four-week period. Lipid levels in the serum and liver were gauged to determine the lipid-reducing effects of HL. Furthermore, gut microbiota composition was elucidated using full-length 16S rRNA gene sequencing. RESULTS: HL notably reduced lipid levels in HFD-induced hyperlipidemic mice. Its efficacy was amplified in hyperlipidemic mice with a hot syndrome but was markedly reduced in those with a cold syndrome. HL treatment led to a decline in alpha-diversity (characterized by ACE, Chao1, Shannon and Simpson index) of the gut microbiota in both sets of mice but affected specific microbial populations based on the syndrome. Specifically, while HL led to a notable increase in Eubacterium, Robinsoniella, and Lachnoclostridium genera, along with the enhancement of Clostridium innocuum and Bacteroides thetaiotaomicron species across all conditions, it syndrome-dependently stimulated Romboutsia ilealis and Parabaceroides_sp_HGS0025 species in mice with hot syndrome. CONCLUSION HL shows stronger lipid-lowering effect on hyperlipidemic mice with hot syndrome, which is in accordance with its traditional usage in clinic. The therapeutic outcomes of HL are intrinsically tied, at least in part, to its modulatory effects on the gut microbiota, offering fresh insights into the foundational principles of traditional Chinese medicine.