Background and Aims: Gut microbiota is closely related to the occurrence and development of hepatocellular carcinoma (HCC). This association suggests that gut microbiota balance should also be an important target for the treatment of HCC in addition to the treatment of primary liver diseases. Therefore, this study was aimed to explore the influencing factors for gut microbiota in patients with HCC. 
Methods: A total of 121 HCC patients were enrolled. Fecal DNA samples of the HCC patients were extracted, and the relative abundance of gut microbiota was analyzed by quantitative real-time PCR. Intestinal dysbacteriosis (ID) was diagnosed by Bifidobacterium/Enterobacteriaceae (B/E) <1. The major factors affecting the gut microbiota in HCC patients were determined by univariate and multiple linear regression analysis .
Results: The abundance of Bifidobacterium was significantly lower than that of Enterobacteriaceae in patients with HCC [Log5 (6.24±1.30)/g vs. Log5(7.59±1.11)/g, P<0.000]. The incidence of ID was 77.69% (94/121). Multiple linear regression analysis showed that monocyte was the only main influencing factor for Bifidobacterium (P<0.000) and ID (P=0.008); total bilirubin (P=0.011), sex (P=0.027) and fasting blood glucose (P=0.038) were the main influencing factors for Enterobacteriaceae. 
Conclusion: Monocyte, total bilirubin, sex and fasting blood glucose are possibly important factors affecting the gut microbiota and thereby cause ID in HCC patients. The correlation between these factors and gut microbiota may not only provide the potential targets for modulating gut microbiota in HCC patients, but also give a solid theoretical basis for gut microbiota intervention as a therapeutic strategy for HCC.