METTL3 and colorectal carcinoma: Human intestinal microbiota can promote or suppress CRC, not only due to the carcinogenic activities of pathogenic bacterium but also caused by the complex effect of wider microbial community, particularly their metabolites, such as deoxycholic acid (DCA), ursodeoxycholic acid and butyrate.39 Recent studies demonstrated that microbiomes have strong effects on the m6A modification and METTL3 expression in mouse brain and intestine.40 However, whether human intestinal microbiota and their metabolites can affect the CRC m6A modification was still unknown.