Liggins Institute, The University of Auckland, 85 Park Road, Grafton, Private Bag 92019, Auckland, 1023, New Zealand.
The Riddet Institute, Palmerston North, 4442, New Zealand.
Eur J Clin Nutr. 2022 Oct;76(10):1415-1422. doi: 10.1038/s41430-022-01119-0. Epub 2022 Apr 22.
BACKGROUND/OBJECTIVES: Self-reported digestive intolerance to dairy foods is common. As dairy can be an important source of dietary protein, this study aimed to identify whether milk protein digestion is compromised in individuals with digestive intolerance.
SUBJECTS/METHODS: Adult women (n = 40) were enroled in this double-blinded, randomised cross-over trial, with digestive symptoms characterised using a lactose challenge and self-reported digestive symptom questionnaire. Participants were classified as either lactose intolerant (LI, n = 10), non-lactose dairy intolerant (NLDI, n = 20) or dairy tolerant (DT, n = 10). In a randomised sequence, participants consumed three different kinds of milk (750 ml); conventional milk (CON), a2 Milk™ (A2M), and lactose-free conventional milk (LF-CON). Circulatory plasma amino acid (AA) concentrations were measured at baseline and every 30 min until 3 h post-ingestion.
In all participants across all milk types, plasma AA concentrations (AUC) increased after milk ingestion with no significant differences in responses observed between milk types or participants (P > 0.05), with the exception of the suppressed lysine response in the DT group following A2M ingestion, relative to the other two groups and milk types (P < 0.05).
Milk protein digestion, as determined by circulatory AAs, is largely unaffected by dairy- and lactose- intolerances.
背景/目的：自我报告的对乳制品的消化不耐受很常见。由于乳制品可以是饮食蛋白质的重要来源，因此本研究旨在确定具有消化不耐受的个体的牛奶蛋白消化是否受损。
研究对象/方法：这项双盲、随机交叉试验纳入了成年女性（n=40），使用乳糖挑战和自我报告的消化症状问卷来描述消化症状。参与者被分为乳糖不耐受（LI，n=10）、非乳糖乳制品不耐受（NLDI，n=20）或乳制品耐受（DT，n=10）。参与者按照随机顺序分别饮用三种不同的牛奶（750ml）：普通牛奶（CON）、A2 牛奶（A2M）和无乳糖普通牛奶（LF-CON）。在基线和摄入后每 30 分钟测量一次循环血浆氨基酸（AA）浓度，直到 3 小时。
在所有参与者和所有牛奶类型中，牛奶摄入后血浆 AA 浓度（AUC）增加，但在牛奶类型或参与者之间没有观察到显著差异（P>0.05），除了 A2M 摄入后 DT 组的赖氨酸反应受到抑制，与其他两组和牛奶类型相比（P<0.05）。
通过循环 AA 测定，牛奶蛋白消化在很大程度上不受乳制品和乳糖不耐受的影响。
