the role of short-chain Fatty acids in the intestine

腔内营养对维持胃肠粘膜结构和功能具有重要意义。特别是，短链脂肪酸(SCFAs)是膳食纤维和抗性淀粉厌氧细菌发酵的代谢产物，作为结肠细胞的首选呼吸燃料尤为重要。单链脂肪酸的多种生物学效应已经被报道，现在有越来越多的实验工作展示了这些分子的新方面。例如，作为SCFAs抗炎作用的中介机制，一些研究人员发现丁酸对促炎细胞因子诱导的NF-kB激活具有抑制作用。现在讨论了各种炎症反应，其中核心作用是核因子-kB的激活，因此抑制核因子-kB的激活代表了膳食纤维和单链脂肪酸在炎症性肠病治疗中的有效性。此外，分子技术的最新进展已经确定了SCFAs抗肿瘤作用的机制。单链脂肪酸可调节细胞周期调节蛋白的表达，并诱导结肠癌细胞的凋亡。单链脂肪酸增加了结肠癌细胞对补体介导的细胞损伤的敏感性。

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.