Alcohol consumption slightly increases the risk of colorectal cancer (CRC).54, 56Studies ofALDH2*2and CRC have yielded inconsistent results.56, 57, 58Fu et al9demonstrated that acetaldehyde entering the gut via bile is metabolized primarily by intestinal ALDH2, with minimal reabsorption, while gut microbiota contributes secondarily.9Thus, the intestinal acetaldehyde exposure time and concentration inALDH2*2allele carriers may change with alcohol consumption. This evidence concerns the gene ALDH2 and colorectal carcinoma.