摘要
Short-chain fatty acids are formed in the colon as a result of microbial fermentation (Bifidobacterium and Lactobacillus) of undigested bioactive carbohydrates, including prebiotics and dietary fiber, and their significant role in orchestrating colon carcinogenesis is of current interest among researchers. Acetate, propionate, and butyrate are the major by-products of SCFA formation. Propionate and butyrate are extensively involved in the cell differentiation, growth arrest, and apoptosis of cancer cells. The anticancer effects of acetate, propionate, and butyrate (molar ratio of approximately 3:1:1) is supported immensely by epidemiological, in vitro and in vivo, studies. The role of lactate has also been considered by several researchers. Diet and dietary habits alter the composition of the gut microflora. An inverse relationship between dietary fiber intake and the incidence of human colon cancer has been observed. Prebiotics and dietary fibers curtail the risk of colon cancer through diverse mechanisms. The interplay between propionate and butyrate, and gastrointestinal epithelial cells (colonocytes) in reducing colon carcinogenesis is a current topic of interest for many researchers. About 70–90 % butyrate is metabolized by the colonocytes. SCFA also modulate colonic and intracellular pH, cell volume, ion transport and regulate cell proliferation, differentiation, and gene expression. Propionate inhibits cell growth and activates apoptosis in colorectal carcinoma cells. Butyrate inhibits histone deacetylase resulting in histone hyperacetylation and growth inhibition in the colonic epithelial cells. This link between histone hyperacetylation, hyperacetylation-induced transcriptional regulation and growth inhibition has been considered as the foremost factors in preventing colon cancer. However, “butyrate paradox,” another concept, has not been confirmed till date. The function of SCFA in the suppression of inflammation and immunomodulation is discussed.
摘要译文
短链脂肪酸由于未消化的生物活性碳水化合物（包括益生元和膳食纤维）的微生物发酵（双歧杆菌和乳杆菌）而在结肠中形成，并且他们在协调结肠癌发生中的重要作用是研究者目前的兴趣。乙酸盐，丙酸盐和丁酸盐是SCFA形成的主要副产物丙酸和丁酸盐广泛参与癌细胞的细胞分化，生长停滞和细胞凋亡。乙酸盐，丙酸盐，和丁酸盐（摩尔比约3：1：1）通过流行病学，体外和体内研究得到了巨大支持。乳酸盐的作用也被一些研究者饮食和饮食习惯改变肠道微生物群落的组成已经观察到膳食纤维摄入与人类结肠癌的发病率之间的反比关系益生元和膳食纤维通过多种机制减少结肠癌的风险丙酸和丁酸之间的相互作用，和胃肠上皮细胞（结肠细胞）在减少结肠癌变中的作用是许多研究者目前关注的话题。大约70％的25％丁酸盐被结肠细胞代谢SCFA还调节结肠和细胞内pH，细胞体积，离子转运和调节细胞增殖，分化和基因表达丙酸抑制细胞生长和激活结肠直肠癌细胞凋亡丁酸盐抑制组蛋白脱乙酰酶，导致组蛋白高乙酰化和结肠上皮细胞中的生长抑制这种组蛋白高乙酰化，高乙酰化诱导的转录调节和生长抑制已被认为是预防结肠癌的最重要的因素。然而，肛门悖论，直至日期尚未得到证实。讨论了SCFA在抑制炎症和免疫调节中的作用
Maya Raman (4); Padma Ambalam (5); Mukesh Doble (4);. Short-Chain Fatty Acids. Probiotics and Bioactive Carbohydrates in Colon Cancer Management[M].DE: Springer, 2016: 97-115