As for gut microbiota, the dysbiosis observed in diabetes may promote tumorigenesis in CRC through at least three mechanisms: low-grade chronic colonic inflammation, corruption of intestinal microbial metabolism (which results in toxic and carcinogenic metabolites) and dysregulation of energy harnessing and nutrient availability by the alteration of various metabolic hormones (e.g., insulin, adiponectin, leptin) [151]. Here, LEP is linked to colorectal carcinoma.