To clarify the lipid-lowering function of 2,4,6-trihydroxybenzaldehyde(phloroglucinaldehyde, PGA) and its effects on gut microbiota, and to investigate whether dark tea extract(DTE) exerts partial lipid-lowering effects by generating PGA(a flavonoid end-product), 18 four-week-old male C57BL/6J mice were randomly divided into 3 groups i.e., the high-fat diet(HFD) group, the sample group(2,4,6-trihydroxybenzaldehyde, abbreviated as the PGA group), and the positive control group(dark tea extract, DTE group). The HFD group was fed a high-fat diet, while the PGA group was given a high-fat diet supplemented with 0.1% PGA standard, and the DTE group received a high-fat diet plus 2.184 g/kg dark tea extract. After continuous feeding for 70 days, samples were collected for serum physiological and biochemical tests, histopathological section observation, and intestinal microbiota analysis. The results showed that compared with the HFD group, the abdominal fat rate and final body weight of mice in both the PGA group and DTE group were significantly reduced(P < 0.05), accompanied by decreased blood lipid levels, increased species diversity of intestinal flora, and reduced relative abundance ratio of Firmicutes to Bacteroidetes(F/B ratio). At the genus level, interventions with PGA and dark tea extract promoted the growth of beneficial bacteria such as Bifidobacterium and Lactobacillus, while inhibiting the proliferation of harmful bacteria including Faecalibaculum, Ralstonia, Eubacterium_brachy_group, and Anaerocolumna. In conclusion, the lipid-lowering effects and changes in intestinal flora were similar between the PGA group and the DTE group. In conclusion, both PGA and DTE exhibit favorable lipid-lowering effects and can improve the intestinal flora of obese mice.