Gut Microbiota and Colorectal Cancer Risk Factors.

Colorectal cancer is a type of gut cancer originating either from the rectum or colon. Genetic and environmental factors, such as the gut microbiome, play pivotal roles in colorectal cancer incidence rates. Therefore, we aimed to review the risk factors of CRC comprising gut bacteriomes and their intra-interactions with each other in the context of CRC development. Gut microbiota alteration, especially bacteriome alteration as the dominant player, seems to be the common feature amongst all risk factors. Although it is not quite obvious whether these alterations are the causes or the consequences of the tumorigenesis risk factors, they are common and almost universal among CRC-affected individuals. In addition, bacterial genotoxicity, biofilm formation, oxidative stress, bacterial metabolome, and dysbiosis are assessed in CRC development. The present study suggests that gut microbial alterations could be the key intermediate, as a cause or a consequence, between most risk factors of CRC and the way they promote or contribute to CRC development.