摘要OBJECTIVE:To investigate composition of gut microbial community in a rat model of functional dyspepsia(FD)and to explore the interventional effects of Simo Tang(四磨汤,SMT).METHODS:A rat model of FD was established through the tail-clamping stimulation method.The rat model of FD was assessed by the state of rats,their weight,sucrose preference rate,and intestinal propulsion rate.The DNA was extracted from stool samples after treatment with SMT.Amplified polymerase chain reaction(PCR)products of the 16S rDNA were sequenced using NovaseQ6000 after construction of libraries.Composition of gut microbial community in the stool samples was determined and analyzed by cluster analysis,bioinformatic analysis,and analysis of α-diversity and β-diversity.RESULTS:The rat model of FD was successfully established using the tail-clamping stimulation method.The statistical results of cluster analysis of operational taxonomic units(OTUs)showed that the relative abundance of OTUs in the FD group was the lowest,while it was the highest in the normal(N)group.The composition of microbiome in the four groups was similar at phyla level.Compared with the FD group,the abundance of Firmicutes was downregulated,and the abundance of Proteobacteria and Bacteroidetes was upregulated in the Simo Tang(SMT)and high-dose Simo Tang(SMT.G)groups.The ratio of Bacteroidetes/Firmicutes was also elevated.According to the analysis of α-diversity and β-diversity,the abundance of flora in FD rats was significantly reduced.The treatment using SMT appeared beneficial to improve the diversity of flora.SMT could improve the intestinal flora in FD rats.The results showed that FD rats had intestinal flora imbalance,and species diversity increased.The results suggested that SMT could regulate the disorders of intestinal flora caused by FD.CONCLUDIONS:SMT could restore gut homeostasis and maintain gut flora diversity by modulating the gut microbiota and its associated metabolites in rats,thereby treating gastrointestinal diseases.