the role of short-chain Fatty acids in the intestine

肠腔营养对维持胃肠道粘膜结构和功能具有重要意义。特别地，短链脂肪酸（SCFA），膳食纤维和抗性淀粉的厌氧细菌发酵的代谢产物，作为结肠细胞的优选呼吸燃料特别重要。SCFAs的各种生物学效应已被报道，现在有越来越多的实验工作显示这些分子的新方面。例如，作为介导SCFA的抗炎作用的机制，一些研究者鉴定了丁酸盐对促炎性精氨酸诱导的NF-κ B活化的抑制作用。现在讨论了各种炎症反应与NF-kB活化的中心作用，因此NF-kB活化的抑制代表了膳食纤维和SCFAs在治疗炎症性肠病中的功效。此外，分子技术的最新进展已经确定了介导SCFAs抗肿瘤作用的机制。SCFAs调节细胞周期调节蛋白的表达并诱导结肠癌细胞凋亡。SCFA增加结肠癌细胞对补体介导的细胞损伤的易感性。

Luminal nutrition is important for maintenance of gastrointestinal mucosal structure and function. In particular, short chain fatty acids (SCFAs), metabolic products of anaerobic bacterial fermentation of dietary fiber and resistant starch, are particularly important as the preferred respiratory fuel of the colonocytes. A variety of biological effects of SCFAs have been reported, and there is now increasing number of experimental works showing new aspects of these molecules. For example, as the mechanisms mediating anti-inflammatory effects of SCFAs, several investigators identified the inhibitory effect of butyrate on proinflammatory cytokine-induced NF-kB activation. Various inflammatory responses are now discussed with the central role of NF-kB activation, and thus the inhibition of NF-kB activation represents the efficacy of dietary fiber and SCFAs in the treatment with inflammatory bowel disease. Furthermore, recent advance in molecular technology has identified mechanisms mediating anti-tumor effects of SCFAs. SCFAs modulate expression of cell cycle-regulating proteins and induce apoptosis in colon cancer cells. SCFAs increase the susceptibility of colon cancer cells to complement-mediated cell injury.