2020年，国际癌症研究机构和世界卫生组织的GLOBOCAN数据库将结直肠癌（CRC）评为全球第三大常见癌症。大多数CRC病例（> 95％）为散发性，来源于可以进展为粘膜内癌和CRC的结直肠息肉。越来越多的证据表明，肠道微生物群落在CRC的发生和进展以及CRC的治疗中可以发挥关键作用，作为重要的代谢和免疫调节因子。决定微生物群落在CRC致癌中的因素包括炎症、肠道干细胞功能的变化、细菌代谢产物对肠粘膜的影响、基因突变的积累和其他因素。在本文中，我讨论了散发性CRC发展的主要机制，提供了与CRC最常关联的细菌的详细特征，并分析了微生物组和微生物代谢产物在炎症启动、促进肠上皮和干细胞的增殖活动以及CRC遗传和表观遗传变化中的作用。我认为在这个方向上开展长期研究非常重要，因为它们为CRC的治疗和预防开辟了新的机会。©作者（们）2023。由百世登出版集团公司出版。版权所有。

In 2020, the International Agency for Research on Cancer and the World Health Organization's GLOBOCAN database ranked colorectal cancer (CRC) as the third most common cancer in the world. Most cases of CRC (> 95%) are sporadic and develop from colorectal polyps that can progress to intramucosal carcinoma and CRC. Increasing evidence is accumulating that the gut microbiota can play a key role in the initiation and progression of CRC, as well as in the treatment of CRC, acting as an important metabolic and immunological regulator. Factors that may determine the microbiota role in CRC carcinogenesis include inflammation, changes in intestinal stem cell function, impact of bacterial metabolites on gut mucosa, accumulation of genetic mutations and other factors. In this review, I discuss the major mechanisms of the development of sporadic CRC, provide detailed characteristics of the bacteria that are most often associated with CRC, and analyze the role of the microbiome and microbial metabolites in inflammation initiation, activation of proliferative activity in intestinal epithelial and stem cells, and the development of genetic and epigenetic changes in CRC. I consider long-term studies in this direction to be very important, as they open up new opportunities for the treatment and prevention of CRC.©The Author(s) 2023. Published by Baishideng Publishing Group Inc. All rights reserved.