Nestlé Institute of Health Sciences, Nestlé Research, Lausanne, Switzerland.
Clinical Development Unit, Nestlé Research Asia, CADC, Singapore.
Clin Nutr. 2019 Aug;38(4):1844-1852. doi: 10.1016/j.clnu.2018.07.016. Epub 2018 Jul 26.
Proteins are major contributors to the beneficial effects of human milk (HM) on preterm infant health and development. Alpha-lactalbumin, lactoferrin, serum albumin and caseins represent approximately 85% of the total HM protein. The temporal changes of these proteins in preterm (PT) HM and its comparison with term (T) HM is poorly characterized.
To quantify and compare the temporal changes of the major proteins in PT HM and T HM.
HM was collected for 4 months postpartum at 12 time points for PT HM (gestational age 28 0/7-32 6/7 weeks; 280 samples) and for 2 months postpartum at 8 time points for T HM (gestational age 37 0/7-41 6/7 weeks; 220 samples). Proteins were measured with a micro-fluidic LabChip system.
Casein, alpha-lactalbumin and lactoferrin decreased with advancing stages of lactation in PT and T HM, whereas serum albumin remained stable. Only marginal differences between PT and T HM were observed for alpha-lactalbumin during postpartum weeks 3-5 and for serum albumin at the first week. However, a comparison of HM provided to preterm and term infants at the same postmenstrual ages revealed that alpha-lactalbumin contents were significantly lower in PT HM than in T HM during the 39-48 postmenstrual weeks.
This study provides comprehensive information of the longitudinal changes of major proteins in PT and T HM, and suggests limited availability of alpha-lactalbumin, a nutritionally important protein, in breastfed PT infants after reaching the term corrected age. This information may be important to optimize HM protein fortification, although its biological relevance needs to be confirmed by intervention studies.
ClinicalTrials.gov (NCT02052245), https://clinicaltrials.gov/ct2/show/NCT02052245.
蛋白质是母乳（HM）对早产儿健康和发育产生有益影响的主要贡献者。α-乳白蛋白、乳铁蛋白、血清白蛋白和酪蛋白约占 HM 总蛋白的 85%。早产儿（PT）HM 中这些蛋白质的时间变化及其与足月（T）HM 的比较特征描述不足。
定量比较和描述 PT 和 T HM 中主要蛋白质的时间变化。
在产后 4 个月内，从 28 0/7-32 6/7 周（280 个样本）的 PT HM 中采集 12 个时间点的母乳，从 37 0/7-41 6/7 周（220 个样本）的 T HM 中采集 8 个时间点的母乳。使用微流控 LabChip 系统测量蛋白质。
在 PT 和 T HM 中，随着泌乳阶段的推进，酪蛋白、α-乳白蛋白和乳铁蛋白逐渐减少，而血清白蛋白保持稳定。仅在产后第 3-5 周观察到 PT 和 T HM 之间α-乳白蛋白和产后第 1 周血清白蛋白之间的微小差异。然而，对在相同的月经后年龄提供给早产儿和足月儿的 HM 进行比较后发现，在 39-48 周的月经后年龄期间，PT HM 中的α-乳白蛋白含量明显低于 T HM。
本研究提供了 PT 和 T HM 中主要蛋白质的纵向变化的全面信息，并表明在达到校正的足月年龄后，母乳喂养的 PT 婴儿中，营养上重要的蛋白质α-乳白蛋白的供应有限。尽管其生物学相关性需要通过干预研究来证实，但这些信息可能对优化 HM 蛋白质强化很重要。
ClinicalTrials.gov（NCT02052245），https://clinicaltrials.gov/ct2/show/NCT02052245。
