Cancer is a major disease burden globally. The gut microbiome and its role in carcinogenesis is a rapidly evolving research field. Mounting evidence has suggested that the gut microbiota is implicated in a variety of cancers especially in the colorectal cancer (CRC). In this connection, detailed and holistic investigations into the gut metagenome in translational research in CRC pathogenesis, diagnosis and response to therapies are imperative. This lecture aims to provide the latest overview and discoveries of the gut microbiota in colorectal neoplasia, including relevant mechanisms in microbiota (pathogen or probiotics)-related carcinogenesis, the potential of utilizing the microbiota as CRC biomarkers, the prospect for modulating the microbiota for CRC prevention or treatment, and the effect of gut microbiome on the therapeutic efficacy of drug through causing drug degradation. These scientific findings will pave the way to clinically translate the use of gut microbiota for CRC in the near future.