Pediatric Epidemiology, Department of Pediatrics, University Medicine Leipzig, 04103 Leipzig, Germany.
Institute of Epidemiology and Medical Biometry, Ulm University, 89075 Ulm, Germany.
Nutrients. 2019 Nov 20;11(12):2842. doi: 10.3390/nu11122842.
The lipid fraction of human milk provides the infant with the fatty acids that are necessary for optimal growth and development. The aim of this study was to investigate the fatty acid composition of human milk at three time points during lactation and its change over time using appropriate statistical methods. Human milk samples from breastfeeding mothers at 6 weeks ( = 706), 6 months ( = 483), and 12 months ( = 81 with all three time points) were analyzed. Centered log-ratio (clr) transformation was applied to the fatty acid data. Principal component analysis (PCA) and generalized linear model-based repeated measure analysis were used to assess changes over time. The total lipid content was significantly higher at 6 months (β = 0.199, < 0.029) and 12 months of lactation (β = 0.421, < 0.001). The constituents of C20:3n-6 and C20:3n-3 were lower at 6 months ( < 0.001). Four distinct sub-compositional fatty acid groups were only identified at 12 months of lactation. The inclusion of small fatty acids of small constituent size in the analysis resulted in a shift in the balance between fatty acid constituents. Human milk fatty acid composition during prolonged lactation is different from that of human milk during a short duration of lactation. Our findings support the hypothesis that a combination of multiple fatty acids is important in fatty acid profiling beyond the presentation of individual fatty acids. Furthermore, the high variability of small fatty acids warrants attention because a compositional analysis may show more pronounced changes.
人乳的脂质部分为婴儿提供了最佳生长和发育所需的脂肪酸。本研究旨在使用适当的统计方法，研究哺乳期三个时间点人乳的脂肪酸组成及其随时间的变化。分析了 6 周（n = 706）、6 个月（n = 483）和 12 个月（n = 81，均有三个时间点）母乳喂养母亲的人乳样本。对脂肪酸数据进行了中心对数比（clr）变换。采用主成分分析（PCA）和基于广义线性模型的重复测量分析来评估随时间的变化。6 个月（β = 0.199， < 0.029）和 12 个月（β = 0.421， < 0.001）哺乳期的总脂质含量显著更高。C20:3n-6 和 C20:3n-3 的成分在 6 个月时较低（<0.001）。只有在 12 个月哺乳期时才鉴定出 4 个不同的亚组成脂肪酸组。在分析中纳入小组成分较小的小脂肪酸会导致脂肪酸成分之间的平衡发生变化。在较长哺乳期内人乳脂肪酸组成与短期哺乳期内人乳脂肪酸组成不同。我们的研究结果支持这样一种假设，即多种脂肪酸的组合对于个体脂肪酸之外的脂肪酸分析很重要。此外，小脂肪酸的高度变异性值得关注，因为组成分析可能会显示出更明显的变化。
