Background Infancy is a critical period of growth and physiological development,in which breast milk is the best source of nutrients.Compared to western countries,research on breast milk of Chinese population are limi...Background Infancy is a critical period of growth and physiological development,in which breast milk is the best source of nutrients.Compared to western countries,research on breast milk of Chinese population are limited.Thus,it is necessary to measure breast milk energy and macronutrient concentrations of healthy urban Chinese mothers at different lactation stages,to expand the database of milk composition of Chinese population,and to examine whether dietary or other maternal factors can affect the levels of macronutrients in breast milk.Methods Breast milk of full expression of one side breast from 436 urban Chinese lactating mothers at 5-11 days,12-30 days,31-60 days,61-120 days,and 121-240 days postpartum was obtained at 9：00 a.m.to 11：00 a.m.Total energy,lactose,protein,and fat contents were measured.24-hour dietary recall was surveyed,and maternal nutrient intakes were analyzed.Results Milk composition changed over the course of lactation and large individual variations were documented.The concentrations were 61.3 kcal/dl for total energy,7.1 g/dl for lactose,0.9 g/dl for protein,and 3.4 g/dl for fat in mature milk.Stage of lactation was a strong factor affecting milk composition.Minimal evidence was found for associations between maternal current dietary intake and milk macronutrient concentration,consistently with prior research.Maternal body mass index （BMI） was positively associated with milk fat content,to a greater extent than did dietary intake.All other maternal characteristics were not significant for milk composition.Conclusion These findings suggest that milk composition is generally weakly associated with maternal factors except for stage of lactation,and is likely to be more susceptible to long-term maternal nutritional status than short-term dietary fluctuation.展开更多
文摘Background Infancy is a critical period of growth and physiological development,in which breast milk is the best source of nutrients.Compared to western countries,research on breast milk of Chinese population are limited.Thus,it is necessary to measure breast milk energy and macronutrient concentrations of healthy urban Chinese mothers at different lactation stages,to expand the database of milk composition of Chinese population,and to examine whether dietary or other maternal factors can affect the levels of macronutrients in breast milk.Methods Breast milk of full expression of one side breast from 436 urban Chinese lactating mothers at 5-11 days,12-30 days,31-60 days,61-120 days,and 121-240 days postpartum was obtained at 9：00 a.m.to 11：00 a.m.Total energy,lactose,protein,and fat contents were measured.24-hour dietary recall was surveyed,and maternal nutrient intakes were analyzed.Results Milk composition changed over the course of lactation and large individual variations were documented.The concentrations were 61.3 kcal/dl for total energy,7.1 g/dl for lactose,0.9 g/dl for protein,and 3.4 g/dl for fat in mature milk.Stage of lactation was a strong factor affecting milk composition.Minimal evidence was found for associations between maternal current dietary intake and milk macronutrient concentration,consistently with prior research.Maternal body mass index （BMI） was positively associated with milk fat content,to a greater extent than did dietary intake.All other maternal characteristics were not significant for milk composition.Conclusion These findings suggest that milk composition is generally weakly associated with maternal factors except for stage of lactation,and is likely to be more susceptible to long-term maternal nutritional status than short-term dietary fluctuation.
文摘目的探讨不同胎龄早产儿母乳中母乳低聚糖(human milk oligosaccharides,HMOs)水平及其对婴儿早期生长发育的影响。方法采用前瞻性队列研究,选取2017年12月1日至2018年11月30日期间在北京大学第三医院出生并母乳喂养的新生儿,分为足月儿组和早产儿组。早产儿组分为超早产儿组(<28周)、极早产儿(28~31+6周)组和晚期早产儿(32~36+6周)组。分别在母亲分娩后7、14、28和120 d收集母乳。本研究共收集到125名产妇的368份母乳样品,其中足月儿母亲54名,晚期早产儿母亲23名,极早产儿母亲39名,超早产儿母亲9名;采用超高效液相色谱-质谱仪测定2-岩藻糖乳糖(2′FL),3-岩藻糖乳糖(3FL),3-唾液酸乳糖(3′SL),α-四糖(P1),乳糖-N-四糖(LNT),乳糖-N-新四糖(LNnT),乳糖-N-五糖Ⅱ(LNFP-Ⅱ),乳糖-N-五糖Ⅴ(LNFP-Ⅴ)8种HMOs浓度。以初乳和过渡乳中2-岩藻糖乳糖(2′FL)浓度大于200μg/mL定义为分泌型母乳。收集婴儿出生后4个月时的体重增长和过敏性疾病发生情况。计数资料组间比较采用χ²检验或Fisher精确检验;计量资料采用Kruskal-Wallis检验和Wilcoxon秩和检验进行组间比较,多组间两两比较采用Nemenyi检验。结果所有产妇中分泌型占79.2%(99/125),不同出生胎龄新生儿母亲分泌型与非分泌型在组间差异无统计学意义(χ^(2)=1.31,P>0.05)。HMOs总浓度在产后1~2周达到峰值,与足月儿相比,早产儿母乳HMOs下降趋势出现较晚,在分泌型分娩后28 d母乳中,晚期早产儿、极早产儿、超早产儿与足月儿组之间HMOs总浓度差异有统计学意义,中位数分别为4587.09、4615.25、5277.44、5476.03μg/mL(Kruskal-Wallis χ^(2)=8.1234,P=0.044)。按照各组在生后4个月的体重增长中位数,分为低体重增长组和高体重增长组,与低体重增长组相比,高体重增长组分娩后7 d时母乳中2-岩藻糖乳糖(2′FL)偏低(1818.04μg/mL vs 2181.67μg/mL,W=1386,P=0.018),而乳糖-N-四糖和乳糖-N-新四糖(LNT&LNnT)偏高(1182.36μg/mL vs 1053.62μg/mL,W=816,P=0.044)。患有过敏性疾病的婴儿母亲分娩后120 d时母乳中3FL含量低于未患有过敏性疾病的婴儿,差异有统计学意义(256.17μg/mL vs 286.18μg/mL,W=564,P=0.026)。结论早产儿母乳中HMOs总体分布概况与足月儿基本一致;早产儿母乳中部分HMO在新生儿体重增长及过敏性疾病的发生发展中可能发挥一定的作用。
