The human gut microbiota consists of approximately 100 trillion microbial cells whose disruption leads to many diseases including inflammatory bowel disease and colorectal cancer to name a few. Recent studies have shown that cancer patients have an altered gut microbiota when compared to healthy controls. Intestinal microbiota has been proposed to contribute to the start and progression of a number of liver diseases, such as alcoholic liver disease (ALD), nonalcoholic steatohepatitis (NASH), liver cirrhosis, hepatic encephalopathy (HE), and hepatocellular carcinoma (HCC). We plan to investigate the relationship between the gut microbiota and the immune system in patients with HCC. In recent years, immune regulation at the level of the tumor microenvironment has become very important in different types of cancer.