Protein, lactose and fat concentration of breast milk of mothers of term and premature neonates

The protein, lactose and fat concentrations in the milk of seven mothers giving birth at term and six mothers giving birth prematurely were determined. Samples were obtained during the first 31 days of lactation. The protein, lactose and fat concentrations of preterm milk were found to be similar to those of fullterm milk over this period. For both term and preterm groups, protein concentration decreased with increasing age, while lactose concentration increased. Fat concentration did not show a consistent pattern of change in the preterm group, but tended to increase with advancing age in the term group.     

Macro-mineral content of milk obtained during early lactation from mothers of premature infants

Milk from mothers giving birth prematurely was analyzed for Na, C1, K, Mg, Ca and P concentrations. The data presented are from analyses of milk samples representative of complete 24-hour expressions and collected serially over the first 29 days of lactation from mothers giving birth at term (FT) and mothers giving birth prematurely (PT).Mineral composition of FT and PT milks was similar during the first month of lactation. With the exceptions of Mg and P, the concentrations of the minerals studied were higher initially than at the end of the fourth week of lactation. From these data, intakes of premature infants fed their own mothers' milk can be estimated and compared to predicted mineral requirements for the premature infant. On the basis of this comparison, we suggest that the quantities provided of Na, C1, K and Mg, but not Ca and P, would be adequate to meet requirements of premature infants during the early weeks of life.     

Zinc,copper and iron content of milk from mothers of preterm and full-term infants

Complete 24-hour expressions of milk were collected over the first month of lactation from mothers giving birth at term (FT) and prematurely (PT). Samples were analyzed for Cu, Fe and Zn concentration. Composition of PT and FT milks was similar during the first 4 weeks of lactation, but the concentrations of each mineral were higher during the first week than during the fourth week. From these data, the intakes of premature infants fed their own mother's milk were estimated and the proportion which must be absorbed and retained in order to accumulate the amounts laid down in utero were predicted. On the basis of these estimates, preterm infants who retain 25% of the Zn and 35% of the Cu in PT milk would approximate in utero accumulations. However, the Fe content of PT milk is unlikely to provide for in utero accretion rates, even if 100% absorption was achieved.     

早产母乳营养成分的分析

目的 探讨早产儿母亲乳汁营养成分的特点及动态变化。方法 收集2012 年11 月至2014 年1月在北京协和医院产科分娩产妇170 人的母乳339 份,用MIRIS 母乳分析仪检测母乳中宏量营养素及能量,比较各组母乳营养成分的差异。结果 （1）早产母乳中蛋白质含量：初乳> 过渡乳> 成熟乳（2.22±0.49 g/dL vs1.83±0.39 g/dL vs 1.40±0.28 g/dL;PPPPP+1~33+6 周组（2.11±0.25 g/dL）和≥ 34 周组（2.22±0.39 g/dL）比较差异有统计学意义（P+1~33+6 周（51±6 kcal/dL vs 58±8 kcal/dL,P+1~33+6 周组和≥ 34 周组（P+1~33+6 周成熟乳蛋白质显著高于≤ 30 周和≥ 34 周组（P结论 （1）早产初乳、过渡乳和成熟乳营养成分差异显著;（2）早产初乳蛋白质显著高于足月初乳,这种差异未能持续到成熟乳阶段;（3）不同孕周早产产妇母乳营养成分亦存在差异,以适应不同胎龄早产儿的营养需要。     

足月儿母乳淀粉酶活性动态变化

为了解我国足月儿母乳淀粉酶活性的动态变化规律,测定40例足月顺产儿乳母不同泌乳期及一次喂奶时前、中、后段乳及母血中淀粉酶的活性。结果显示初乳中淀粉酶活性为(9772.37±1.70)IU/L;随着泌乳期的延长,淀粉酶活性逐渐下降;一次喂奶前、中、后段乳中淀粉酶的活性差异无显著性意义;母乳淀粉酶98％为唾液型淀粉酶;母乳中淀粉酶活性高于母血100倍;产妇年龄与母乳淀粉酶活性无显著性相关。提示母乳中含有丰富的淀粉酶,对母乳喂养儿的淀粉消化和潜在的抗感染作用具有积极意义,应向广大群众大力提倡母乳喂养。     

Leptin determination in colostrum and early human milk from mothers of preterm and term infants

Background

Leptin is involved in the regulation of food intake and energy expenditure and is therefore important for growth and brain development. Analytical methods used for leptin measurement in human milk differ widely in the literature and yield varying results.

Aims

To compare different preparation methods for the analysis of leptin in human milk and to investigate the leptin levels in colostrum and mature human milk from mothers of preterm or term infants.

Methods

Mothers delivering a preterm (n = 37) or a term infant (n = 40) were recruited for a prospective study and were ask to collect breast milk on the 3rd and 28th day of lactation. Leptin, protein and fat concentrations were analysed. Clinical data of mother and child were recorded prospectively.

Results

Skim milk was most appropriate for leptin analysis. Human milk leptin concentrations did not differ between preterm and term human milk. In term milk, leptin concentration on day 28 was lower than on day 3 (p < 0.05). Milk leptin levels on the 3rd and 28th day were positively correlated with mothers' body mass index, but not with fat content in milk.

Conclusion

Skim milk was the most stabile preparation for leptin analysis. Preterm and term human milk contain leptin in equal concentrations. Human milk leptin depends on mothers' body mass index.     

Longitudinal changes in milk composition of mothers delivering preterm and term infants

The concentrations of protein nitrogen (PN), non-protein nitrogen (NPN), energy, fat, sodium (Na), calcium (Ca), phosphorus (P), magnesium (Mg), and zinc (Zn) were determined in human milk from mothers giving birth to full-term (n = 13) and preterm infants (n = 8). Milk samples were collected under controlled conditions at two-week intervals for 12 weeks postpartum. Statistically significant differences in PN, Ca, and P concentrations were detected between the milk from mothers of preterm and term infants. The mean PN concentration in the preterm milk was statistically higher than that of term milk (198 vs. 164 mg N/dl), in contrast to the lower mean Ca (220 vs. 261 mg/1) and P (125 vs. 153 mg/1) concentrations detected in the preterm milk. No other differences in mean nutrient concentration were observed between the two groups. Concentrations of PN, NPN, Na, P, and Zn decreased over time. The concentration of Mg increased slightly. The content of fat, energy, and Ca did not change.     

Concentrations of IL-10 in preterm human milk and in milk from mothers of infants with necrotizing enterocolitis

BACKGROUND: Despite the protective effects of human milk against necrotizing enterocolitis, the incidence is highest in the extremely premature infant, and only minimally decreased with feeding human milk. This suggests that certain protective agents may be lower in milk from mothers delivering extremely premature infants. The anti-inflammatory cytokine IL-10 was one possibility. AIM: We hypothesized that low concentrations of IL-10 in preterm milk contribute to the development of necrotizing enterocolitis in extremely premature infants. METHODS: IL-10 in human milk collected at weeks 1, 2, and 4 postpartum was measured by ELISA in mothers of infants born extremely premature at 23-27 wk gestation (group EP), premature at 32-36 wk gestation (group P), and term at 38-42 wk gestation (group T). Single milk samples were collected from a separate group of mothers whose infants developed necrotizing enterocolitis. RESULTS: There were no significant differences in concentrations of milk IL-10 among groups EP, P, or T. Concentrations of IL-10 declined as lactation progressed (p < 0.001). IL-10 in milk was frequently undetected in all groups, but even more so in the milk of the group of women whose infants had necrotizing enterocolitis (86%) than in groups EP (40%) and P (27%) (p < 0.01). CONCLUSION: IL-10 was present in preterm milk from most women, and the concentrations in preterm and term milk were not significantly different. A paucity of IL-10 in human milk was found in certain mothers in each group, especially in those whose infants developed necrotizing enterocolitis.     

High proportions of n-6 polyunsaturated fatty acids in mature milk of mothers in Ouagadougou, Burkina Faso

Milk from 101 mothers living in Ouagadougou (Burkina Faso) showed a mean lipid content of 33.42 g/l and a fatty acid composition strongly related to the mothers' dietary habits: high proportions of linoleic acid (19.80%), n-6 long-chain polyunsaturated fatty acids (1.90%), and 8:0-14:0 saturated fatty acids (26.94%). Conclusion: The proportions of alpha-linolenic acid (0.45%) and n-3 long-chain polyunsaturated fatty acids (0.44%) were low. The 18:2/18:3 and n-6/n-3 long-chain polyunsaturated fatty acids ratios (53:1 and 5:1, respectively) were well above recommendations.     

Breast milk from mothers of very low birthweight infants: variability in fat and protein content

While breast milk appears to be superior to formula for the development of very low birthweight (VLBW) infants, it is supplemented to meet the metabolic demands of the rapidly growing premature infant. To estimate the nutritional variability of breast milk from mothers of VLBW infants, protein (bicinchoninic acid method) and fat content (creamatocrit) were measured in breast-milk spot samples from mothers of 20 VLBW infants, collected 4 times a day during the first 4 wk of lactation. Protein content (median 1.9 g dl(-1), range 1.1-3.5 g dl(-1)) and fat content (3.8/1.0-14.6 g dl(-1)) were highly variable and lacked a normal distribution over all samples and in individual women's milk. There was only a weak correlation between fat and protein (rs=0.416, p < 0.001). Fat but not protein was lower in morning samples than in samples collected later in the day (p < 0.001). Protein but not fat content decreased during the weeks of lactation (rs =-0.446, p < 0.001). No impact of the baby's gestational age was observed. CONCLUSION: The fat and protein content of breast milk from mothers of VLBW infants is highly variable, calling into question the clinical feasibility of individualized supplementation of breast milk for VLBW infants based on spot sample measurements.     

Comparison of the phospholipid classes in human milk in Japanese mothers of term and preterm infants

Background: Phospholipids (PLs) play an essential role in the growth and brain development of infants. Aim: To investigate PL composition in human milk (HM), including lysophosphatidylcholine, phosphatidylethanolamine, phosphatidylinositol, phosphatidylserine, phosphatidylcholine (PC) and sphingomyelin (SM), from healthy Japanese mothers. Analyses were performed on colostrum, transitional milk and mature milk from mothers of preterm and term infants. Methods: HM samples were collected from mothers of 15 term infants (term group) and of 19 preterm infants (preterm group). PL composition was determined by two-dimensional thin-layer chromatography in conjunction with phosphorus analysis. Results: In both groups, the PL content (% of total lipid) of mature milk was significantly lower than in colostrum. SM and PC were the main PLs in HM, but in the preterm group, the percentage of SM in mature milk was significantly higher and PC in mature milk was significantly lower than in the term group.

Conclusion: The transition from colostrum to mature milk leads to an increase in SM and a decrease in PC in the HM of preterm infants, along with a decrease in PL content. This is the first report to demonstrate the differences in PL composition in HM between mothers of preterm and term infants.     

Long‐chain polyunsaturated fatty acids decline rapidly in milk from mothers delivering extremely preterm indicating the need for supplementation

Aim

Our aim was to perform an in‐depth analysis of the composition of fatty acids in milk from mothers delivering extremely preterm babies. We investigated longitudinal changes in milk fatty acid profiles and the relationship between several types of fatty acids, including omega‐3 and omega‐6.

Methods

Milk samples were collected at three stages of lactation from 78 mothers who delivered at less than 28 weeks of pregnancy at the Sahlgrenska University Hospital, Gothenburg, Sweden, from April 2013 to September 2015. Fatty acid composition was analysed by gas chromatography–mass spectrometry.

Results

A reduction in long‐chain polyunsaturated fatty acids (LCPUFAs) was observed during the lactation period. The concentrations of arachidonic acid and docosahexaenoic acid declined from medians of 0.34 to 0.22 mol% and 0.29 to 0.15 mol%, respectively, between postnatal day 7 and a postmenstrual age of 40 weeks. Strong correlations were found between the intermediates of several classes of fatty acids, including omega‐3, omega‐6 and omega‐9.

Conclusion

A rapid reduction in LCPUFA content in the mother's milk during the lactation period emphasises the importance of fatty acid supplementation to infants born extremely preterm, at least during the period corresponding to the third trimester, when rapid development of the brain and adipose tissue requires high levels of LCPUFAs.     

Inhibition of enteropathogenic Escherichia coli adhesion to HEp-2 cells by colostrum and milk from mothers delivering low-birth-weight neonates

Breast milk samples from three groups of Brazilian women were evaluated for their inhibitory effect on enteropathogenic Escherichia coli (EPEC) adhesion to HEp-2 cells: G1, mothers delivering preterm babies of appropriate birth weight (n = 12); G2, mothers delivering term babies of low birth weight (n = 11); G3, the control group, mothers delivering term babies of appropriate birth weight (n = 39). Colostrum samples were obtained at 48–72 h and milk samples on the 7th, 30th and 60th days after delivery. All samples showed strong inhibitory activity (66%–100%), without significant differences among the three groups and four periods. Total IgA and anti-EPEC IgA concentrations were significantly higher in colostrum than in milk samples in the three groups studied. The levels of colostral IgA and anti-EPEC IgA observed in G1 and G2 were significantly higher compared to the control group. Western blotting assays showed that individual samples as well as pools of colostrum or milk samples contain IgA antibodies to many EPEC outer membrane proteins. A 94 kDa band with molecular weight consistent with the EPEC adhesin named intimin, was recognized by all samples analysed. Bands of different molecular weight were also recognized by some samples of colostrum and milk, such as a band of ∼ 18.4 kDa, with molecular weight equivalent to bundle-forming pilus subunits. Conclusion Our results suggest that colostrum and milk from mothers of premature and small-for-date term neonates are as effective in protecting the newborn against EPEC infections as those from mothers of term babies of appropriate birth weight. Received: 14 July 1996 / Accepted: 12 October 1996     

Nutritional relevance of trans isomeric fatty acids in human milk

Trans isomeric fatty acids amount to about 2% of the fatty acid composition of human milk in Europe, whereas lower values were seen in Africa, and higher values were reported for North-America. At least five human studies indicate that trans fatty acids may interfere with the metabolism of long-chain polyunsaturated fatty acids.

Conclusion: Trans isomeric fatty acids in human milk should be regarded as a potential confounding variable in studies investigating the role of long-chain polyunsaturated fatty acids in the development of breastfed infants.     

Human milk mineral intake and serum concentrations of calcium and phosphorus in newborn term infants: influence of intrauterine growth restriction

A prospective case-control study was performed to test the hypothesis that the milk Ca and P contents of term, small-for-gestational-age (SGA) newborns' mothers differs from that of term, adequate-for-gestational-age (AGA) newborns' mothers. We studied 71 pairs of mothers and newborns, divided into two groups: I (control): 41 pairs of mothers and term AGA newborns and II (study): 30 pairs of mothers and term SGA newborns. This latter group was subdivided according to type (symmetric: birthweight, length and head circumference <10th percentile; asymmetric: birthweight <10th percentile) and severity (P3 - P3 - 相似文献   

Availability of donor milk improves enteral feeding but has limited effect on body growth of infants with very‐low birthweight: Data from a historic cohort study

Compare with preterm formula, donor human milk (DM) is associated with a lower risk of mortality and morbidity in preterm infants. It is thus deemed superior to preterm formula as the sole diet or supplement to own mother''s milk (OMM) for preterm infants, especially for those with very low birthweight (VLBW). This historic cohort study investigated the relationship between DM availability, and enteral feeding, body growth of VLBW infants by comparing two cohorts before and after the establishment of a human milk bank. A sub‐analysis was also conducted between small‐for‐gestational‐age (SGA) and non‐SGA infants in our cohorts. Our results showed that DM availability was associated with earlier initiation and faster advancement of enteral feeding, earlier attainment of full enteral feeding, and a higher proportion of OMM in enteral feeding. DM availability was also associated with earlier regain of birthweight, but not with better body growth. SGA and non‐SGA infants responded differently to DM availability with only the non‐SGA group showing improved enteral feeding associated with DM availability. The poor growth of VLBW infants with fortified DM warrants further investigations on better fortification strategies to further improve body growth. Studies are also needed on long‐term effects of DM feeding on the development of VLBW infants.     

Low soluble Fas (sFas) and sFas ligand (sFasL) content in breast milk after preterm as opposed to term delivery

AIM: Various mechanisms of innate immunity and gastrointestinal integrity are potentially affected by soluble Fas (sFas) and sFas ligand (sFasL). Assuming that sFas and sFasL in milk reflect cellular events during lactogenesis, we aimed to assess the impact of premature parturition and duration of lactation on the concentrations of sFas and sFasL in human milk. PATIENTS AND METHODS: The content of the soluble form of the cell surface receptor Fas (sFas) and its natural ligand (sFasL) was measured in human breast milk of 44 healthy mothers after preterm (<35 wk, n=21) and term (>37 wk, n=23) delivery. Milk was furthermore classified as immature breast milk (days 4-7 of lactation) or mature breast milk (days 35-45 of lactation). Breast milk (2-3 ml) was sampled 5 min after the start of breastfeeding by manual expression or milk pump, and stored at -20 degrees C until analysis by an ELISA. RESULTS: sFas and sFasL concentrations were lower in immature milk after preterm compared to term delivery (sFas: 1.71; 1.38-2.47 ng/ml vs 3.03; 2.02-4.30 ng/ml, p < 0.001; sFasL: 0.13; 0.07-0.21 ng/ml vs 0.29; 0.15-0.60 ng/ml, p < 0.001 [median +/- interquartile range]). Mature milk samples, taken 1 mo later from both gestational groups, did not differ in sFas/sFasL content. Soluble Fas was positively correlated with sFasL in the same sample of immature (p < 0.001) and mature human milk (p < 0.05). A positive correlation was found between sFas and sFasL in immature and mature milk samples of the same mother (p < 0.01). The body mass index of the mothers and duration of pregnancy were positively correlated with the sFas and sFasL content in immature milk (p < 0.05 and p < 0.01, respectively) but not in mature milk. CONCLUSION: Preterm newborn infants fed with breast milk have a lower intake of sFas and sFasL compared to term neonates. Our results demonstrate that preterm delivery affects breast milk composition.