背景:婴儿配方奶粉(IFs),母乳的唯一适当替代品,是复杂的基质,需要大量的成分和加工步骤,这可能会影响蛋白质消化和随后的氨基酸吸收。
目的:目的是了解IFs中蛋白质成分质量对餐后血浆氨基酸(AA)谱的影响。
方法:使用来自不同来源(奶酪与理想乳清)和变性水平(IFs-A/-B/-C),和具有不同超分子组织的酪蛋白(IFs-C/-D)。十只尤卡坦小型小猪(12至27天大)用作人类婴儿模型,根据威廉姆斯拉丁广场,收到每个IF3天,接下来是2天的清洗期。在第3天,从餐前10分钟至餐后4小时定期采样颈静脉血浆以测量游离AAs,尿素,胰岛素和葡萄糖浓度。数据采用饮食混合线性模型(IFs)进行统计分析,时间和性别为固定因素,仔猪为随机因素。
结果:用奶酪乳清制成的IFs(IFs-A和-B)比用理想乳清制成的IFs(IF-C和-D)引起的血浆总AA和必需AA浓度明显更高,无论餐前和餐后时间。餐后观察到的大多数差异都可以通过AA稳态修饰来解释。基于奶酪乳清的IFs诱导Thr的血浆浓度增加,这是由于这些IFs中的Thr含量较高以及仔猪中的Thr限制降解能力。使用非胶束酪蛋白成分导致血浆中AA分解代谢标志物含量降低(IF-Dvs.IF-C)。
结论:总体而言,我们的结果强调了IFs中蛋白质成分质量(组成和结构)对新生儿血浆AA谱的重要性,这可能会进一步影响婴儿的蛋白质代谢。
BACKGROUND: Infant formulas (IFs), the only adequate substitute to human milk, are complex matrices that require numerous ingredients and processing steps that may impact protein digestion and subsequent amino acid (AA) absorption.
OBJECTIVE: The objective was to understand the impact of the protein ingredient quality within IFs on postprandial plasma AA profiles.
METHODS: Four isonitrogenous and isocaloric IFs were produced at a semi-industrial scale using whey proteins from different origins (cheese compared with ideal whey) and denaturation levels (IF-A, -B, -C), and caseins with different supramolecular organizations (IF-C, -D). Ten Yucatan minipiglets (12- to 27-d-old) were used as a human infant model and received each IF for 3 d according to a Williams Latin square followed by a 2-d wash-out period. Jugular plasma was regularly sampled from 10 min preprandial to 4 h postprandial on the third day to measure free AAs, urea, insulin, and glucose concentrations. Data were statistically analyzed using a mixed linear model with diet (IFs), time, and sex as fixed factors and piglet as random factor.
RESULTS: IFs made with cheese whey (IF-A and -B) elicited significantly higher plasma total and essential AA concentrations than IFs made with ideal whey (IF-C and -D), regardless of the pre- and postprandial times. Most of the differences observed postprandially were explained by AA homeostasis modifications. IFs based on cheese whey induced an increased plasma concentration of Thr due to both a higher Thr content in these IFs and a Thr-limiting degrading capability in piglets. The use of a nonmicellar casein ingredient led to reduced plasma content of AA catabolism markers (IF-D compared with IF-C).
CONCLUSIONS: Overall, our results highlight the importance of the protein ingredient quality (composition and structure) within IFs on neonatal plasma AA profiles, which may further impact infant protein metabolism.