OBJECTIVE  To explore the effects of four kinds of heat-clearing and dampness-drying herbs on intestinal flora, bile acids and short chain fatty acids (SCFAs) in normal mice at long-term clinical equivalent doses.

  METHODS  Thirty Balb/c male mice were randomly divided into control group, Sophora flavescens Ait. (KS) group, Phellodendron chinense Schneid. (HB) group, Coptis chinensis Franch. (HL) group and Scutellaria baicalensis Georgi (HQ) group, with 6 mice in each group. Except for the control group, KS group, HB group, HL group and HQ group were orally administrated at a dosage of 2.34 g·kg^-1, 3.12 g·kg^-1, 1.3 g·kg^-1 and 2.6 g·kg^-1, respectively, for two weeks. The contents of short chain fatty acids and bile acids in feces were detected by liquid chromatography tandem mass spectrometry, and the structural changes of microflora in intestinal contents were detected by 16S rRNA high-throughput gene sequencing technology.

  RESULTS  There was no significant effect of heat-clearing and dampness-drying Chinese medicine on the contents of six short-chain fatty acids in the feces of normal mice. Among the 23 common bile acids, when compared with the control group, the numbers of the significantly changed bile acids in HQ group, KS group, HL group and HB group were 4, 3, 2 and 1, respectively. From the perspective of changes in the abundance of intestinal flora, compared with the control group, except for the KS group, Firmicutes in the HL group, HQ group and HB group all showed a downward trend, and the Bacteroides showed an upward trend, among which the changes in the HL group were the most significant.

  CONCLUSION  Sophora flavescens Ait., Phellodendron chinense Schneid., Coptis chinensis Franch. and Scutellaria baicalensis Georgi have little effect on SCFAs in normal mice, but can affect bile acid content by changing the structure of intestinal flora.