Nestle Nutrition R&D Centers, Minnetonka, MN 55343, USA.
Nutr Clin Pract. 2012 Apr;27(2):281-94. doi: 10.1177/0884533611434933. Epub 2012 Mar 5.
Nucleotides are low molecular weight biological molecules key to biochemical processes. Sources include de novo synthesis, recovery via salvage mechanisms, and dietary intakes. Although endogenous production serves as the main nucleotide source, evidence suggests that exogenous sources are essential to immune competence, intestinal development, and recovery. Dietary nucleotides serve a marked role in rapidly proliferating cells where they are necessary for optimal function. Accordingly, dietary nucleotides are deemed conditionally essential in the presence of various physiological stresses, including growth and development, recovery from injury, infection, and certain disease states. Clinical studies that evaluated nutrition formulations of nucleotides in combination with other specific nutrient substances demonstrated improved clinical outcomes in patients characterized as critically ill, injured, immune suppressed, or with chronic gastrointestinal conditions. However, conclusions regarding specific benefits of nucleotides are limited. Scientific substantiation of nucleotide supplementation in infant formula has been reported to improve the maturation and development of the intestinal tract as well as immune function. All medical nutrition products except for one immune-modulating formulation are devoid of nucleotides. In an effort to build on this, the current review presents the data to support potential clinical applications for nucleotides in enteral nutrition that may contribute to improved outcomes in physiologically stressed patients.
核苷酸是生物小分子，是生化过程的关键。其来源包括从头合成、通过补救机制回收以及饮食摄入。虽然内源性产生是核苷酸的主要来源，但有证据表明，外源性来源对于免疫功能、肠道发育和恢复至关重要。在快速增殖的细胞中，膳食核苷酸起着显著的作用，它们是最佳功能所必需的。因此，在存在各种生理应激（包括生长和发育、受伤恢复、感染和某些疾病状态）的情况下，膳食核苷酸被认为是条件必需的。评估核苷酸与其他特定营养物质相结合的营养配方的临床研究表明，在危重、受伤、免疫抑制或患有慢性胃肠道疾病的患者中，改善了临床结果。然而，关于核苷酸具体益处的结论是有限的。据报道，在婴儿配方奶粉中添加核苷酸可以改善肠道的成熟和发育以及免疫功能。除了一种免疫调节配方外，所有的医学营养产品都不含核苷酸。为了在此基础上更进一步，本综述提供了支持核苷酸在肠内营养中潜在临床应用的数据，这可能有助于改善生理应激患者的结局。
