目前的研究多是强调短链脂肪酸( SCFAs)在结直肠癌防治中的有益作用,如:通过抑制肠道慢性炎症反应,给肠 道上皮细胞提供能量和维持肠黏膜上皮稳态,从而降低结直肠癌的发生率。 此外,SCFAs 还可以通过拮抗组蛋白去乙酰化 酶(HDACs) ,抑制结肠癌细胞增殖;通过活化 caspase-3 信号通路,促进肿瘤细胞凋亡,以及激活抗肿瘤免疫,对结直肠癌产 生治疗作用。 然而,最近的流行病学研究显示,结直肠癌患者血液中,部分 SCFAs 水平升高,是促进结直肠癌发生的危险因 素。 在肠道中补充产丁酸细菌,可促进小鼠结直肠癌的发生,敲除细菌中产丁酸基因,促癌作用受到抑制。 另有临床研究, 在肿瘤患者的血液中发现,高水平丁酸可以抑制伊匹木单抗诱导的 T 细胞以及白介素-2 浸润,降低了细胞毒 T 淋巴细胞 相关抗原 4 抗体治疗肿瘤的效果。 这些研究提示 SCFAs 在结直肠癌的防治中发挥有益作用是在一定条件下的,超出这个 范围会产生负面作用。 因此,在临床工作中应用 SCFAs 预防和治疗结直肠癌的同时,需要警惕 SCFAs 不恰当的应用产生的 负面作用。

Current studies mostly emphasize the beneficial role of short-chain fatty acids SCFAs in the prevention and treatment of colorectal cancer such as reducing the incidence of colorectal cancer by inhibiting chronic intestinal inflammatory response providing energy to intestinal epithelial cells and maintaining intestinal mucosal epithelial homeostasis. In addition SCFAs can inhibit the proliferation of colon cancer cells by antagonizing histone deacetylases HDACs . By activating caspase-3 signaling pathway tumor cell apoptosis can be promoted and anti-tumor immunity can be activated which has therapeutic effects on colorectal cancer. However recent epidemiological studies have shown that elevated levels of some SCFAs in the blood of colorectal cancer patients are risk factors for the development of colorectal cancer. Further studies showed that intestinal supplementation of butyric-producing bacteria promoted the development of colorectal cancer in mice and the cancer-promoting effect was inhibited by knockdown of the butyric-producing gene of bacteria. In other clinical studies high levels of butyric acid have been found in the blood of tumor patients to inhibit ipilimumab induced T cells and interleukin-2 IL-2 infiltration and reduce the efficacy of cytotoxic T lymphocyte associated antigen 4 CTLA4 antibody in tumor treatment. These studies suggest that SCFAs play a beneficial role in the prevention and treatment of colorectal cancer under certain conditions beyond which there will be negative effects. Therefore when applying SCFAs in clinical work for the prevention and treatment of colorectal cancer it is necessary to guard against the negative effects of inappropriate application of SCFAs.