Department of Paediatrics, University of Pécs, Pécs, Hungary.
J Pediatr Gastroenterol Nutr. 2010 Mar;50(3):316-20. doi: 10.1097/MPG.0b013e3181a9f944.
To compare fatty acid composition of human milk at 2 different stages of lactation and investigate the relation between trans isomeric and long-chain polyunsaturated fatty acids (LCPUFAs) in human milk at the sixth month of lactation.
We investigated human milk samples obtained at the sixth week and sixth month of lactation from 462 mothers who participated in a large birth cohort study. Fatty acid composition of human milk lipids was determined by high-resolution capillary gas-liquid chromatography.
Fat contents of human milk increased significantly between the sixth week and sixth month of lactation (1.63 [2.06] and 3.19 [3.14], g/100 mL; median [interquartile range], P < 0.001). Percentage contributions to human milk fatty acid composition of nearly all polyunsaturated fatty acids also increased significantly (linoleic acid: 10.09 [4.41] and 11.01 [4.53], arachidonic acid: 0.46 [0.32] and 0.48 [0.23], alpha-linolenic acid: 0.69 [0.42] and 0.75 [0.41], and docosahexaenoic acid: 0.17 [0.23] and 0.23 [0.15], % wt/wt, P < 0.001). Values of the 18-carbon trans octadecenoic acid (C18:1n-7/9t) significantly inversely correlated to linoleic acid (r = -0.24, P < 0.001), alpha-linolenic acid (r = -0.19, P < 0.001), and arachidonic acid (r = -0.43, P < 0.001). In contrast, we found no correlation between the 16-carbon trans hexadecenoic acid (C16:1n-7t) and the same LCPUFAs.
Data obtained in the present study indicate increasing fat contents with stable or increasing percentage contribution of LCPUFAs in human milk samples between the sixth week and at the sixth month of lactation, and the availability of 18-carbon trans isomeric fatty acids is inversely associated to the availability of several LCPUFAs in human milk at the sixth month of lactation.
比较哺乳期两个不同阶段人乳的脂肪酸组成，并研究人乳中第六个月长链多不饱和脂肪酸（LCPUFAs）与反式异构体的关系。
我们调查了来自参加大型出生队列研究的 462 名母亲在哺乳期第六周和第六个月的人乳样本。通过高分辨率毛细管气相色谱法测定人乳脂质的脂肪酸组成。
人乳中的脂肪含量在哺乳期的第六周和第六个月之间显著增加（1.63[2.06]和 3.19[3.14]，g/100mL；中位数[四分位距]，P<0.001）。几乎所有多不饱和脂肪酸对人乳脂肪酸组成的百分比贡献也显著增加（亚油酸：10.09[4.41]和 11.01[4.53]，花生四烯酸：0.46[0.32]和 0.48[0.23]，α-亚麻酸：0.69[0.42]和 0.75[0.41]，二十二碳六烯酸：0.17[0.23]和 0.23[0.15]，wt/wt%，P<0.001）。18-碳反式十八碳烯酸（C18：1n-7/9t）的值与亚油酸（r=-0.24，P<0.001）、α-亚麻酸（r=-0.19，P<0.001）和花生四烯酸（r=-0.43，P<0.001）呈显著负相关。相比之下，我们没有发现 16-碳反式十六碳烯酸（C16：1n-7t）与相同的 LCPUFAs 之间存在相关性。
本研究获得的数据表明，在哺乳期的第六周和第六个月之间，人乳样本中的脂肪含量增加，而长链多不饱和脂肪酸的百分比贡献稳定或增加，并且 18-碳反式异构体脂肪酸的可用性与人乳中几种 LCPUFAs 在第六个月的可用性呈负相关。
