Food Phytochemistry Department, Instituto de la Grasa (CSIC), Campus Universitario, Building 46, 41013, Sevilla, Spain.
Food Lipid Biomarkers and Health Group, Institute of Food Science Research (CIAL, CSIC-UAM), 28049, Madrid, Spain.
J Dairy Sci. 2020 Sep;103(9):7742-7751. doi: 10.3168/jds.2020-18428. Epub 2020 Jul 1.
Human colostrum is the first milk secreted by the mother after birth and constitutes the ideal food for the newborn, because its chemical composition, rich in immunoglobulins, antimicrobial peptides, growth factors, bioactive lipids, and other important molecules, is perfectly adapted to the metabolic, digestive, and immunological immaturity of the newborn. An incomplete gestational period can affect the maturity of the mammary gland and its ability to secrete milk with the proper composition for the newborn's condition. Previous studies indicate that the mammary gland modulates the profiles of bioactive lipids present in the different phases of lactation from colostrum to mature milk. Given the key role played by the polar lipids (PL) (phospho- and sphingolipids) of the milk fat globule membrane (MFGM) in the immune system and cognitive development of the newborn, it is crucial to analyze whether the content and distribution of the PL are affected by gestation period. Therefore, this study aimed to determine the milk fat globule (MFG) and MFGM lipid compositions of human colostrum samples from 20 healthy preterm and full-term mothers. Lipid characterization using chromatographic techniques (gas chromatograph mass spectrometry and HPLC-evaporative light-scattering detection) revealed differences related to length of gestation in the profiles of lipid classes and fatty acid and triacylglyceride contents of colostrum. This comparative analysis leads to noteworthy outcomes about the changing roles of the PL, considering the preterm or full-term condition. We found a lack of correlation of some PL (such as phosphatidylcholine, phosphatidylinositol, and phosphatidylserine) with the delivery term; these could be denoted as structural category lipids. However, sphingomyelin and phosphatidyl-ethanolamine exhibited trends to decrease in full-term colostrum, indicating that in the final stage of pregnancy specific accretion of some PL occurs, which should be denoted as a nutritional redistribution.
人初乳是人母产后最初分泌的乳汁，是新生儿的理想食物，因为其化学成分富含免疫球蛋白、抗菌肽、生长因子、生物活性脂质和其他重要分子，与人乳在新生儿代谢、消化和免疫不成熟期完美适应。不完全的妊娠期会影响乳腺的成熟度及其分泌适合新生儿状况的具有适当组成的乳汁的能力。先前的研究表明，乳腺会调节从初乳到成熟乳不同泌乳阶段中存在的生物活性脂质的特征。鉴于乳脂肪球膜 (MFGM) 中的极性脂质 (PL)（磷和鞘脂）在新生儿免疫系统和认知发育中的关键作用，分析 PL 的含量和分布是否受妊娠期影响至关重要。因此，本研究旨在确定 20 位健康早产和足月母亲的人初乳样本中的乳脂肪球 (MFG) 和 MFGM 脂质组成。使用色谱技术（气相色谱-质谱联用和 HPLC-蒸发光散射检测）进行的脂质特征分析揭示了与胎龄相关的脂质类和脂肪酸以及初乳三酰甘油含量特征的差异。这种比较分析得出了关于 PL 不断变化的作用的有意义的结果，考虑到早产或足月的情况。我们发现一些 PL（如磷脂酰胆碱、磷脂酰肌醇和磷脂酰丝氨酸）与分娩期限缺乏相关性；这些可以被称为结构类别脂质。然而，鞘磷脂和磷脂酰乙醇胺在足月初乳中表现出减少的趋势，表明在妊娠的最后阶段，一些 PL 会发生特定的积累，这应该被称为营养再分配。
