Accumulating evidence supports the role of microbes in mediating a pathogenic link between environmental factors, including diet and lifestyle, and colorectal carcinogenesis.12,164 Experimental evidence suggests that high-fat diet and cigarette smoking promote colorectal carcinogenesis through the modulation of gut microbiota and metabolites.165 Analyses of two longitudinal prospective cohort studies by Arima et al. have shown that the association of a Western-style diet with colorectal cancer incidence is stronger for tumors containing higher amounts of pks+Escherichia coli. This evidence concerns the gene ARAF and colorectal cancer.