The body of a human has a vast array of microorganisms termed the microbiome that impacts almost every function of the body. Gene-environment interactions play a major role in making us susceptible to cancer and the microbiome is such an environmental factor that we are exposed to from the very beginning of our lives to the very end. Increasing pieces of evidence are pointing towards an association of cancer and the microbiome. The bacteria inside our body might help us prevent some cancers as well as may increase the risk of carcinogenesis and treatment responses. Many studies are suggesting that tinkering with the microbiome might be a new way to treat and prevent many kinds of cancer. Although information on the roles of the microbiome in carcinogenesis is scant and almost no direct links have been found between these two yet. This review offers some of the recent evidences of the association between cancer and the microbiome, discuss the impact of gut bacteria on cancer and provide a detailed discussion on gut microbiota mediated therapeutic approaches with a special focus on Hepatocellular Carcinoma. The implementation of the new knowledge discovered in this subject calls for a great deal of research.