结直肠癌（CRC）的病因受到定植在胃肠道的细菌群落的影响。这些微生物从无法消化的饮食或宿主衍生化合物中获取必需营养，并激活必要的分子信号通路以维持正常的组织和免疫功能。联想和机械性研究已经确定了一些可能增加CRC风险的细菌物种，包括Fusobacterium nucleatum，肠毒素产生性Bacteroides fragilis和pks + E. coli等值得注意的例子。近年来，这项工作已经从宿主基因突变状态、肿瘤内微生物异质性、短暂感染以及序贯或共同定植后多种致癌细菌的累积影响扩展到包括更广泛的方面。在本综述中，我们将提供更新的概述，介绍宿主和细菌互动如何影响CRC的发展，以及如何利用此知识诊断或预防CRC，以及肠道微生物群如何影响CRC治疗的疗效。

The etiology of colorectal cancer (CRC) is influenced by bacterial communities that colonize the gastrointestinal tract. These microorganisms derive essential nutrients from indigestible dietary or host-derived compounds and activate molecular signaling pathways necessary for normal tissue and immune function. Associative and mechanistic studies have identified bacterial species whose presence may increase CRC risk, including notable examples such as Fusobacterium nucleatum, Enterotoxigenic Bacteroides fragilis, and pks+ E. coli. In recent years this work has expanded in scope to include aspects of host mutational status, intra-tumoral microbial heterogeneity, transient infection, and the cumulative influence of multiple carcinogenic bacteria after sequential or co-colonization. In this review, we will provide an updated overview of how host-bacteria interactions influence CRC development, how this knowledge may be utilized to diagnose or prevent CRC, and how the gut microbiome influences CRC treatment efficacy.