Abstract: Objective To study the effect of Poria on behavior and intestinal microflora of chronic unpredictable depression stress model rats. Methods A chronic unpredictable mild stress (CUMS) model of rats was used to conduct a sugar water preference experiment to evaluate the lack of pleasure in rats administered with Poria cocos, and an open field experiment was used to analyze the behavior of rats. 16 rRNA gene sequencing method for intestinal flora species difference analysis. Results Compared with the normal group, the model group's body weight and sugar water consumption rate decreased significantly, autonomous activity was significantly weakened, the intestinal flora species richness and species diversity decreased, and the levels of Bacteroides and Proteobacteria at the portal level increased High, the level of thick-walled phylum decreased, and the level of genus lactic acid bacteria decreased; after the rats were given Poria powder, compared with the model group, the body weight and sugar water consumption of Poria powder group increased significantly (P<0.05), autonomous Significantly increased activity (increased moving distance, increased number of entry into the center, increased number of verticals) and the difference was extremely significant (P<0.01), intestinal flora species richness and species diversity increased, Bacteroidetes and Proteobacteria at the portal level The level of phylum decreased, the level of thick-walled phylum increased; the level of lactic acid bacteria at the genus level increased. Conclusion Poria cocos powder can achieve anti-depressive effect by reducing the level of Bacteroidetes and Proteobacteria, and restoring the level of Pachyphyta and Lactobacillus.

Key words: Poria, antidepressant, chronic unpredictable stress, open field experiment, intestinal flora