Colorectal cancer (CRC) is the most common cancer in the world, and its incidence has been increasing in recent years. The occurrence of CRC is believed to be related to a variety of factors. Epidemiological data indicate that CRC is mainly affected by environmental factors, eating habits, physical activity and genetic factors. As a newly recognized functional component, the intestinal microbiota plays important roles in preventing CRC formation and maintaining intestinal immunity.

In this review, we summarize the mechanisms by which the gut microbiota causes CRC through alterations to immune function, focusing on the mechanisms by which intestinal microbial dysfunction promotes CRC. Furthermore, we describe the changes in the intestinal flora observed in CRC and their potential for CRC treatment with the goal of facilitating future research on the roles of the intestinal flora.

结直肠癌（CRC）是世界上最常见的癌症，其发病率近年来呈上升趋势。CRC的发生被认为与多种因素有关。流行病学资料表明，结直肠癌主要受环境因素、饮食习惯、体力活动和遗传因素的影响。作为一种新发现的功能成分，肠道菌群在预防结直肠癌的形成和维持肠道免疫方面发挥着重要作用。

在这篇综述中，我们总结了肠道微生物群通过改变免疫功能导致结直肠癌的机制，重点关注肠道微生物功能障碍促进结直肠癌的机制。此外，我们描述了在 CRC 中观察到的肠道菌群变化及其对 CRC 治疗的潜力，目的是促进未来对肠道菌群作用的研究。