Objective · To explore the changes of gut microbiota in polycystic ovary syndrome (PCOS) model rats and to study the possible role of gut microbiota in the pathological progress of PCOS. Methods · Six-week-old female Sprague Dawley rats were randomly divided into control group and experimental group (n10 per group). Subcutaneous injection with dehydroepiandrosterone (DHEA) in 0.2 mL phosphate buffer saline (PBS) was adopted to establish PCOS model rats, while the control group rats were subcutaneously injected with the same amount of PBS. After treatment for 4 weeks, the estrous cycle, ovarian weight and morphology were detected. The change of relative abundance of gut microbiota was detected with high-throughput Illumina sequencing technique. Results · Ovarian weight in experimental group was lower than that in control group (P0.010). The estrous cycle was disrupted and ovarian morphology was greatly changed with enlarged follicles and polycystic ovaries, indicating successful PCOS rat model inducedDHEA. Relative abundance of gut microbiota was significantly altered in genus level, with enrichment of genus Alloprevotella (P0.040) and Parasutterella (P0.009) in experimental group. Several kinds of microbial taxa, such as Alphaproteobacteria, Betaproteobacteria, Deltaproteobacteria, Burkholderiale, Elusimicrobia, Elusimicrobiales, Elusimicrobiaceae, and microbial genera Elusimicrobium, Parasutterella and Allobaculum, were remarkably enriched in experimental group, while the abundance of Psychrobacter, Odoribacter and Moraxellaceae were reduced compared with control group revealedLEfSe analysis (LDA ≥ 2.0). Conclusion · The gut microbiota in PCOS model rats is greatly changed compared with that of control group. Many kinds of microbial taxa varies significantly in abundance, suggesting there might be close association between gut microbiota and occurrence and development of PCOS.