Abstract: This study aimed to explore changes of gut microbiota in experimental model rats with psychological suboptimal health state (PSHS). The experimental rats were given a variety of stresses, including orphaned, uncertain empty bottle stress, circadian disorder and other stresses to simulate PSHS caused by various stress events in human life. Open field test, elevated cross maze, blood biochemical indexes and other auxiliary models were used to evaluate the experimental animal model. Changes of gut microbiota were studied by 16S rRNA gene high-throughput sequencing. All experimental protocols were approved by the Animal Ethics Committee of the Biomedical Research Laboratory of Shanxi University. Compared with the control group, the body weight of PSHS group gained slowly (P<0.01). In addition, the numbers of crossings and rearings in the open field test, and the percentage of time and entries in the open arms, were significantly reduced compared to the control group (P<0.05). But there were no significant change in the percentage of sucrose preference, blood biochemical, blood routine examination and so on. Gut microbiota analyses showed that the diversity of gut microbiota in PSHS model rats changed, and the relative abundances of 10 species of gut microbiota changed significantly (P<0.05, P<0.01), including Bacilli, Lactobacillales, Lactobacillaceae, Lactobacillus, Clostridia, Clostridiales, Blautia, Coriobacteriales, Coriobacteriaceae, and Adlercreutzia. To some extent, the established PSHS model rats reflect the state of humans with PSHS. By studying the changes of gut microbiota in the animal model with PSHS, this study provided an important reference for explaining the physiological change due to PSHS and formulating relevant measures of intervention.