Key Laboratory for Animal Disease Resistance Nutrition of the Ministry of Education of China, Animal Nutrition Institute, Sichuan Agricultural University, Ya'an, 625014, People's Republic of Chin.,
Amino Acids. 2010 Aug;39(3):633-40. doi: 10.1007/s00726-010-0502-x. Epub 2010 Feb 17.
Sulfur amino acids (SAA), particularly methionine and cysteine, are critical for the gut to maintain its functions including the digestion, absorption and metabolism of nutrients, the immune surveillance of the intestinal epithelial layer and regulation of the mucosal response to foreign antigens. However, the metabolism of SAA in the gut, specifically the transmethylation of methionine, will result in a net release of homocysteine, which is shown to be associated with cardiovascular disease and stroke. Furthermore, the extensive catabolism of dietary methionine by the intestine or by luminal microbes may result in a decrease in nutritional efficiency. Therefore, the regulation of SAA metabolism in the gut is not only nutritionally relevant, but also relevant to the overall health and well-being. The superiority of DL-2-hydroxy-4-methylthiobutyrate to DL-methionine in decreasing homocysteine production, alleviating stress responses, and reducing the first-pass intestinal metabolism of dietary methionine may provide a promising implication for nutritional strategies to manipulate SAA metabolism and thus to improve the nutrition and health status of animals and perhaps humans.
硫氨基酸（SAA），特别是蛋氨酸和半胱氨酸，对肠道维持其功能至关重要，包括营养物质的消化、吸收和代谢、肠道上皮层的免疫监视以及对外来抗原的黏膜反应的调节。然而，SAA 在肠道中的代谢，特别是蛋氨酸的转甲基化，会导致同型半胱氨酸的净释放，同型半胱氨酸与心血管疾病和中风有关。此外，肠道或腔微生物对膳食蛋氨酸的广泛分解代谢可能导致营养效率降低。因此，肠道中 SAA 代谢的调节不仅与营养有关，而且与整体健康和福祉有关。DL-2-羟基-4-甲基硫丁酸在降低同型半胱氨酸生成、缓解应激反应和减少膳食蛋氨酸的第一肠内代谢方面优于 DL-蛋氨酸，这可能为操纵 SAA 代谢的营养策略提供了有希望的启示，从而改善动物甚至人类的营养和健康状况。
