Molecular Mechanisms of Gut Microbiota-Associated Colorectal Carcinogenesis

Colorectal cancer (CRC) is the cancer occurring in colon and rectum, and is the fourth leading cause of tumor-associated deaths worldwide. As a multi-etiological cancer, CRC could be induced by genetic and environmental factors, including unhealthy diet, irregular lifestyle, inappropriate inflammatory, and the dysbiosis of gut microbiota. Since immunotherapy has been the most popular cancer therapy nowadays, the relationships among gut microbiota, host immune cells and CRC pathogenesis are widely investigated. Scientists constantly tried to figure out the underlying mechanisms involved to support the further therapeutic studies. In this review, we discuss the component shifts of gut microbiota in CRC patients compared with healthy people, summarize how immune cells participate in protecting host from pathogenic microbes, elaborate the molecular mechanisms involved in gut microbiota-associated carcinogenesis of colonic epithelial cells and look into how gut microbiota influence the CRC therapy.