结直肠癌发病率和死亡率居我国全部恶性肿瘤的第 3 和第 5 位，严重威胁居民健康。结直肠癌病因复杂，其中 肠道微生态是影响癌变过程的关键环节。肠道菌群是维持人体胃肠道及机体健康的重要因素，肠道微生物病原体在结直肠 癌发病机制包括微生物代谢、宿主免疫和炎症途径的调节、氧化应激与抗氧化防御调节、细菌基因毒素等环节。传统中药 给药方式主要为口服，中药进入胃肠道后不可避免与肠道微生物发生相互作用。中药主要通过调节肠道菌群结构，从而调 节宿主免疫功能，以及氧化应激与抗氧化防御调节等途径实现防治结直肠癌的作用。实验研究证实，中药对肠道微生态系 统的平衡具有很好的保护作用，对菌群失调具有改善作用；中药可以提高宿主抗癌免疫反应以及通过调节肿瘤微环境下的 骨髓来源的细胞功能发挥抗肿瘤疗效；促进有氧培养菌的耐酸能力并抑制了厌氧培养菌的耐酸能力，从而增强了整体肠道 菌群的抗氧化性。另外，中药亦能改善微生物的代谢、减轻代谢性炎症，以及抑制产生大肠杆菌的体外和体内基因毒性， 中草药的药效成分经肠道微生物转化后发挥抗炎、镇痛和抗肿瘤等药理作用。综上，肠道菌群在部分结直肠癌的发生发展 中具有重要作用，调节肠道菌群是中医药防治结直肠癌的重要靶标。

In China, the morbidity and mortality of colorectal cancer ranks the third and fifth place of all malignant tumors, which seriously threatens the health of residents. The etiology of colorectal cancer is complex, and gut microbiota is the key factor in the process of carcinogenesis. Gut microbiota is an important factor to maintain the human gastrointestinal tract and body health. The pathogenesis by which gut microbiota induce colorectal cancer includes microbial metabolism, immune and inflammatory pathways and the regulation of stress and antioxidant defense, bacterial gene toxin and so on. Traditional Chinese medicine (TCM) is often taken by oral, so it inevitably interacts with the gut microbiota. TCM mainly regulates the composition of gut microbiota, thereby regulates the host immune function, as well as oxidative stress and antioxidant defense regulation and other ways to achieve the role of prevention and treatment of colorectal cancer. The experimental studies have confirmed that TCM has a good protective effect on the balance of intestinal microecology system and improvement of the flora imbalance. It can improve that anti-cancer immune reaction of the host and exert the anti-tumor curative effect by regulating the cell function of bone marrow source, enhance oxidation resistance of the whole intestinal flora, improve the metabolism of microorganisms, reduce metabolic inflammation, and inhibit the in vitro and in vivo genotoxicity of escherichia coli, and anti-inflammation, analgesia, anti-tumor and so on. To sum up, intestinal flora play an important role in the occurrence and development of some colorectal cancer, and regulating intestinal flora is an important target of TCM for the prevention and treatment of colorectal cancer.