Macronutrient Content Of Human Milk Research Articles

Macronutrient composition of human milk from Korean mothers of full term infants born at 37-42 gestational weeks.

BACKGROUND/OBJECTIVESBreast milk is the best available food for optimum growth and development of infants and the breastfeeding rate is increasing in Korea. The purpose of this study is to measure the concentrations of macronutrients and to evaluate their changes according to lactation period in breast milk from lactating Korean women.SUBJECTS/METHODSMilk samples were obtained from 2,632 healthy lactating women (mean age; 32.0 ± 3.3 years), where the lactating period was up to a period of 8 months, who also volunteered to participate in the Human Milk Macronutrient Analysis Research. Lactose, protein, fat and water content in the breast milk samples were analyzed with infrared spectrometry using MilkoScan FT-2.RESULTSThe mean macronutrient composition per 100 mL of mature breast milk was 7.1 g for lactose, 1.4 g for protein and 3.0 g for fat, and energy content was 61.1 kcal. The protein concentration was significantly lower in milk samples at 1-2 weeks (2.0 g/dL) to 2-3 months (1.4 g/dL) than those at 0-1 week (2.2 g/dL), but it was similar among samples from 3-4 months to 7-8 months (1.3 g/dL). Mean lipid levels varied among different lactational period groups (2.7-3.2 g/dL), but presented no significant difference. Lactose concentration in the milk samples did not differ with lactation period. Maternal body mass index was positively related to protein and lipid breast milk contents, but was negatively related to lactose content. General linear models examining the associations between maternal variables and milk macronutrient content revealed that lactation period had a major impact on protein and lipid, but not on lactose content in breast milk.CONCLUSIONSThese results warrant future studies to explore factors that may be associated with changes in macronutrient content in human milk.

Intake and macronutrient content of human milk given to extremely preterm infants.

Human milk (HM) is the preferred basis of nutrition for infants, including those born prematurely. Information on HM macronutrient content is necessary to optimize nutritional support of preterm infants. This study aimed to describe the types and amounts of enteral feeds given to Swedish extremely preterm infants during hospitalization and to investigate the energy and macronutrient contents in HM given to these infants. A population-based study of Swedish extremely preterm infants (n = 586) born before 27 gestational weeks was conducted. Data on ingested volumes of different milk during hospitalization and analyses of macronutrient content in HM samples were obtained from hospital records. Nutritional content of HM was determined by mid-infrared spectrophotometry analysis. During the first 4 weeks of life, 99% of the infants were exclusively fed HM, and at 4 weeks of life, 70% of the infants received only mother's own milk (MOM). Nutritional content in 821 MOM samples was analyzed. Protein content in MOM decreased significantly from 2.2 to 1.2 g/100 mL during the first 112 postpartum days, whereas fat and energy content were highly variable within and between MOM samples. In addition, 354 samples of donor milk were analyzed. Content of protein, fat, and energy in pooled donor milk (n = 129) was lower compared to single donor milk. Swedish extremely preterm infants receive MOM to a large extent during hospitalization. Protein, carbohydrates, and energy in MOM changed significantly with time. Weekly analyses of MOM during the first month of lactation would allow more individualized nutritional support for these vulnerable infants.

Identification of the Variability of Metabolites in Human Milk using Gas Chromatography‐Mass Spectrometry (GC‐MS) Profiling

A significant amount of research has been conducted into the macronutrient content of human milk. As such, the variation of milk components such as fat, protein and lactose have been well defined, however, little is known about the metabolites in human milk. Our preliminary investigation has detected approximately 200 metabolites in human milk. In this study we investigated the metabolites present in milk using GC‐MS profiling. Mothers (n=10) of healthy infants (1–18 months) provided approximately 5ml of freshly expressed breastmilk for analysis. Samples were mixed with methanol and snap frozen at −80ºC. Metabolites were extracted and GC‐MS was performed to obtain a metabolite profile for each sample. Data analysis was performed using Analyzer Pro® software. Whilst many of the metabolites in these profiles are yet to be identified, we were able to determine which of the metabolites exhibited the greatest variation. The profiling of these metabolites provides a platform for future research into the metabolic pathways that exhibit the greatest variation in the lactating human breast. These techniques will allow further elucidation of the physiology of the lactating human breast and have the potential to assist in the use of milk samples for the diagnosis of lactation difficulties such as mastitis and inadequate milk supply. Funded by an unrestricted research grant from Medela AG, Switzerland.

Human milk macronutrient analysis using point-of-care near-infrared spectrophotometry

To demonstrate that the real-time nutritional analysis of human milk carbohydrate, fat and protein with near-infrared (NIR) spectrophotometric methods is accurate. A prospective study of the measurement of the macronutrient content of human milk. Milk was first analyzed on the SpectraStar 2400 Near Infrared Analyzer (Unity Scientific, Columbia, MD, USA), and then sent for primary chemical analysis for fat, protein and carbohydrate. Forty-two samples were used to create a calibration file. Ten samples were then used to validate the machine. After logistic regression analysis, the validation set had a correlation (r (2)) of 0.91 for carbohydrates, 0.95 for fat and 0.95 for protein. This study demonstrates the feasibility of the use of NIR for nutrient analysis of human milk. NIR offers the potential for analysis and adjustable fortification of human milk to optimize nutrient intake for the high-risk neonate.

Near-infrared reflectance analysis to evaluate the nitrogen and fat content of human milk in neonatal intensive care units

Objective:To validate near-infrared reflectance analysis (NIRA) as a fast, reliable and suitable method for routine evaluation of human milk’s nitrogen and fat content.Setting:One neonatal intensive care unit.Patients:124 samples of expressed...

Fat Content in Human Milk According to Duration of Lactation

To the Editor .— We read with interest the article by Mandel et al1 that showed that the fat content of human milk increased after prolonged breastfeeding. They mention that very little is known about milk composition during prolonged lactation and refer to only 2 studies. We previously published an article on this topic.2 We analyzed the macronutrient content of human milk from 244 mothers who had a surplus of breast milk that was donated to a milk bank. At the time of our study, there were no limitations on the length of time after birth during which the mother could continue to …

Maternal energy balance and lactation performance of Mesoamerindians as a function of body mass index

The effect of maternal energy balance in conjunction with body energy reserves on lactation performance has not been fully elucidated in humans. Energy balance was computed from changes in weight and body composition over 6 mo postpartum in 21 Otomi Indian women with relatively low postpartum body mass indexes (BMIs; in kg/m2, 21.4 +/- 0.9) and 19 with relatively high BMIs (25.7 +/- 1.9). Body fat was determined by deuterium dilution. Milk production was estimated by 24-h test weighing. Macronutrient content of human milk was measured by standard techniques. In both groups weight declined over the 6 mo postpartum (P = 0.04). In the lower BMI group only, body fat (kg, % of wt) decreased significantly (P = 0.04). Milk fat concentration was positively correlated with body fat at 3 and 6 mo (r = 0.32 and 0.40; P = 0.04 and 0.01, respectively). Energy balance was not associated with milk production or composition, nutrient secretion into milk, or infant growth velocity, except at 6 mo, when energy balance was positively correlated with milk energy and fat concentration in the lower BMI group (r = 0.55; P = 0.01). Fat concentration was lower in the lower BMI group (P = 0.04). Because of the inverse correlation between milk production and milk fat at 3 and 6 mo (r = -0.47 and -0.43, respectively; P = 0.01), fat secretion into milk did not differ between groups. Infant growth velocities did not differ significantly between groups. In conclusion, negative energy balance in conjunction with lower energy reserves did not adversely affect lactation performance or infant growth in this population of Otomi Indians.

The Copenhagen Cohort Study on Infant Nutrition and Growth: breast-milk intake, human milk macronutrient content, and influencing factors

In 91 healthy term infants breast-milk intake was measured at 2, 4, and 9 mo by test weighing and human milk macronutrient content by infrared analysis every 2-4 wk. In infants exclusively breast-fed, mean milk intake was 781 and 855 mL/24 h at 2 and 4 mo, respectively, and correlated positively with the current weight of the infant and negatively with the amount of formula supplement given at the maternity ward. Median daily energy intake was considerably below current recommendations (423 and 381 kJ/kg body wt at 2 and 4 mo, respectively). Protein concentration in the milk was approximately 8% higher in primipara. Median daily protein intake was 1.3 and 1.0 g/kg body wt at 2 and 4 mo, respectively. Median fat concentration was 39.2 g/L and was positively associated with pregnancy weight gain. This supports the hypothesis that maternal fat stores laid down during pregnancy are easier to mobilize during lactation than are other fat stores and, if low, may limit milk fat when exhausted.

Energy and macronutrient content of human milk during early lactation from mothers giving birth prematurely and at term

The lactose, lipid, protein, and total energy content of milk produced during the first 4 wk of lactation was determined in milk from mothers giving birth prematurely and at term. Milk samples analyzed were representative of complete 24-h expressions. Over the first 4 wk of lactation lactose concentration increased, but nitrogen concentration decreased by an average of 25%. Lipid and total energy concentration increased by 25% from the 1st to 2nd wk and then remained stable in both groups. Although these changes with duration of lactation were similar in both groups, premature compared to full term milk was consistently 20 to 30% higher in total energy and lipid concentration, 15 to 20% higher in total protein and, after the 1st wk, approximately 10% lower in lactose. By comparing predicted nutrient intakes to estimated requirements of premature infants fed 150 to 200 ml/kg/day of their own mothers' milk, we predict that the quantities of protein and energy provided would be adequate to meet the needs of the infant during the early weeks of life.