中国不同哺乳阶段母乳中氨基酸含量研究

AMINO ACID CONTENTS IN BREAST MILK AT DIFFERENT LACTATION STAGES IN CHINESE WOMEN

目的分析中国不同哺乳阶段母乳中17种氨基酸含量的普遍水平。方法在兰州、广州、成都、天津、上海、长春六个地区招募单胎足月分娩的健康产妇共690例,采集其1~5、10~15、40~45、200~240、300~400 d的母乳,使用全自动氨基酸分析仪和高效液相色谱仪测定母乳中的氨基酸含量。结果母乳中总氨基酸及各单体氨基酸含量随着哺乳时间的延长呈下降趋势,200d后基本趋于稳定。母乳中含量最丰富的单体氨基酸是谷氨酸,其次是亮氨酸,含量最低的是蛋氨酸,其次是色氨酸,各单体氨基酸在总氨基酸中的比例变化趋势不同。不同地区母乳中17种氨基酸含量在初乳阶段差异最大,但各氨基酸占总氨基酸的比例在各哺乳阶段差异都较小。结论不同哺乳阶段、不同地区间母乳中氨基酸的含量及其占总氨基酸的比例存在一定程度的差异,这为中国婴幼儿配方食品国家标准中必需氨基酸推荐含量的调整与制定以及不同年龄段婴幼儿配方食品的研发提供理论参考。[营养学报,2020,42 (5):435-441]

Objective To determine the levels of 17 amino acids in breast milk at different lactation stages in Chinese women.Methods Milk samples from 690 healthy lactating mothers with full-term delivery were collected at 1-5,10-15,40-45,200-240 and 300-400 days after they gave birth.The contents of amino acids were quantified by automatic amino acid analyzer and HPLC(high performance liquid chromatography).Results The contents of total and individual amino acids decreased as lactation progresses,and were stable after 200 days.Glutamic acid was the most abundant amino acid,followed by leucine,while methionine was the least abundant amino acid,followed by tryptophan.Colostrum varied significantly among the six geographic locations in total amino acid content,but the pattern of amino acids was similar at each lactation stage among the six geographic locations.Conclusion The contents of total amino acids in breast milk and the proportion of individual amino acids varied significantly over different lactation stages and geogarphic locations,which provides theoretical reference for the recommended essential amino acids contents in infant formulas,and developing formula foods for infants and young children of different ages in China.