Dos Reis Sandra A, da Conceição Lisiane L, Siqueira Nathane P, Rosa Damiana D, da Silva Letícia L, Peluzio Maria do Carmo G
Department of Nutrition and Health, Universidade Federal de Viçosa, Viçosa, Minas Gerais, 36570-900, Brazil.
Nutr Res. 2017 Jan;37:1-19. doi: 10.1016/j.nutres.2016.11.009. Epub 2016 Nov 23.
The purpose of this review is to discuss the potential mechanisms of probiotics action in colorectal cancer prevention. In this regard, the composition of the intestinal microbiota is considered as an important risk factor in the development of colorectal cancer, and probiotics are able to positively modulate the composition of this microbiota. Studies have shown that the regular consumption of probiotics could prevent the development of colorectal cancer. In this respect, in vitro and experimental studies suggest some potential mechanisms responsible for this anticarcinogenic action. The mechanisms include modification of the intestinal microbiota composition, changes in metabolic activity of the microbiota, binding and degradation of carcinogenic compounds present in the intestinal lumen, production of compounds with anticarcinogenic activity, immunomodulation, improvement of the intestinal barrier, changes in host physiology, inhibition of cell proliferation, and induction of apoptosis in cancer cells. In contrast, very few reports demonstrate adverse effects of probiotic oral supplementation. In light of the present evidence, more specific studies are needed on probiotic bacteria, especially regarding the identification of the bacterial strains with greater anticarcinogenic potential; the verification of the viability of these strains after passing through the gastrointestinal tract; the investigation of potential adverse effects in immunocompromised individuals; and finally establishing the dosage and frequency of use.
本综述的目的是探讨益生菌在预防结直肠癌方面的潜在作用机制。在这方面，肠道微生物群的组成被认为是结直肠癌发生的一个重要风险因素，而益生菌能够积极调节这种微生物群的组成。研究表明，经常食用益生菌可以预防结直肠癌的发生。在这方面，体外和实验研究提示了一些导致这种抗癌作用的潜在机制。这些机制包括改变肠道微生物群的组成、微生物群代谢活性的变化、肠道腔内致癌化合物的结合与降解、具有抗癌活性的化合物的产生、免疫调节、肠道屏障的改善、宿主生理的变化、细胞增殖的抑制以及癌细胞凋亡的诱导。相比之下，极少有报告表明口服补充益生菌有不良影响。鉴于目前的证据，需要对益生菌进行更具体的研究，特别是关于鉴定具有更大抗癌潜力的菌株；这些菌株在通过胃肠道后的活力验证；免疫功能低下个体潜在不良反应的调查；以及最终确定使用剂量和频率。
