Nutritional and functional importance of intestinal sulfur amino acid metabolism
Nutritional and functional importance of intestinal sulfur amino acid metabolism
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DOI：
10.1093/jn/135.7.1609
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发表时间：
2005-07-01
影响因子：
4.2
通讯作者：
Burrin, DG
中科院分区：
文献类型：
--
作者：
Shoveller, AK;Stoll, B;Burrin, DG
含硫氨基酸、蛋氨酸和半胱氨酸的代谢与人类健康和细胞功能的几个关键方面有关。此外，通过胃肠道代谢膳食氨基酸对于正常功能在营养上是重要的。在含硫氨基酸（SAA）的情况下，在体内，在成人中的稳定同位素研究表明，内脏组织利用高达30-44%的饮食蛋氨酸和半胱氨酸。同样，全胃肠外营养（TPN）喂养仔猪的蛋氨酸需要量降低30%，这是一种膳食营养素主要绕过肠道代谢的情况。这些数据表明，蛋氨酸的肠道代谢是相当大的，但肠道代谢的命运饮食蛋氨酸在很大程度上是未知的。饮食中的半胱氨酸可能作为谷胱甘肽的前体在肠上皮抗氧化功能中起关键作用。此外，半胱氨酸和谷胱甘肽也可以通过调节氧化还原状态来调节上皮细胞增殖。最近的证据表明，转化的结肠上皮细胞能够甲硫氨酸转甲基化和转硫。这篇综述讨论了肠道SAA代谢的证据，以及这如何影响营养需求和上皮功能。
The metabolism of sulfur amino acids, methionine and cysteine, has been linked to several key aspects of human health and cellular function. In addition, the metabolism of dietary amino acids by the gastrointestinal tract is nutritionally important for normal function. In the case of sulfur amino acids (SAAs), in vivo, stable isotope studies in adults suggest that the splanchnic tissues utilize as much as 30-44% of the dietary methionine and cysteine. Similarly, the dietary methionine requirement is 30% lower in total parenteral nutrition (TPN)-fed piglets, a condition in which dietary nutrients largely bypass intestinal metabolism. These data suggest that intestinal metabolism of methionine is substantial, yet the intestinal metabolic fate of dietary methionine is largely unknown. Dietary cysteine likely plays a key role in intestinal epithelial antioxidant function as a precursor for glutathione. Moreover, cysteine and glutathione may also regulate epithelial cell proliferation via modulation of redox status. Recent evidence indicates that transformed colonic epithelial cells are capable of methionine transmethylation and transsulfuration. This review discusses the evidence of intestinal SAA metabolism and how this affects nutrient requirements and epithelial function.