Composition Of Human Milk Research Articles

Comparative Proteomics of Human Milk From Eight Cities in China During Six Months of Lactation in the Chinese Human Milk Project Study.

Human milk (HM) is the golden standard of infant nutrition that can protect immature body function and enhance nutrition metabolism to ensure infant growth. Region specificity and lactation period could change the protein composition in HM. In this research, proteomics analysis was used to compare proteomes across eight cities, namely Harbin, Lanzhou, Guangzhou, Chengdu, Jinhua, Weihai, Zhengzhou, and Beijing, which represented the northeast, northwest, southeast, southwest, east, and north and central regions of China,. Proteins varied significantly among the cities. These different proteins were mainly involved in the process of platelet degranulation, innate immune response, and triglyceride metabolic process, which might be due to different living environments. These differences also lead to variation in protection and fat metabolism from mothers to infants in different cities. Four proteins were expressed differently during 6 months of lactation, namely Dipeptidyl peptidase 1, Lysozyme C, Carbonic anhydrase 6, and Chordin-like protein 2. The changes in these proteins might be because of the change of growth needs of the infants. The findings from our results might help to improve the understanding of HM as well as to design infant formula.

The effect of risk at birth on breastfeeding duration and exclusivity: A cohort study at a Brazilian referral center for high-risk neonates and infants

Background and aimBoth breastfeeding and the use of human milk are strategies that provide better conformation to health throughout an individual’s life and bring countless short- and long- term benefits, which are well established in the scientific literature. For at-risk newborns (NBs), these strategies are crucial interventions to enable neonatal survival with better quality of life due to the distinctive and complex composition of human milk, which serves as personalized food-medicine-protection. However, there is limited knowledge about breastfeeding practices in high-risk NBs. The aim was to estimate the duration of EBF and to investigate the effect of risk at birth on EBF discontinuity in the first six months of life’.MethodsThis cohort study included 1,003 NBs from a high-risk referral center, followed up from birth to the sixth month of life, between 2017 and 2018. Correspondence and cluster analysis was used to identify neonatal risk clusters as the main exposure. The object of interest was the time until EBF discontinuity. The Kaplan-Meier methods and the Cox proportional hazards model were used to estimate the hazard ratio and 95% confidence intervals.ResultsThe prevalence and median duration of EBF decreased proportionally in the three groups. The multiple model revealed a gradient in EBF discontinuity, which was 40% higher in risk group 1 and 111% higher in risk group 2 compared to healthy full-term NBs. Additionally, EBF during hospitalization predicted a longer median duration of this practice for high-risk NBs.ConclusionThis study confirms a high proportion of high-risk NBs who have EBF discontinued before six months of life. The risk of EBF discontinuity is higher in risk groups, with a gradual effect even when adjusted by several factors. Effective interventions are needed to promote, protect, and support breastfeeding in different profiles of risk-at-birth groups.

Oxytocin Regulates the Expression of Selected Colostrum-derived microRNAs.

The highly expressed microRNAs (miRNAs) in milk are known as beneficial miRNAs, such as mir148a-3p, which is related to immune system development and disease prevention. There is a need to study their expression and secretion regulatory mechanism in breast milk. We hypothesize that oxytocin can be involved in the regulation of expression and secretion of milk-derived miRNAs. Initially, oxytocin's effect on miRNA expression in human mammary cells was analyzed. Secondly, the expression of selected miRNAs in mothers' colostrum treated or not with oxytocin before, during, or after labor was compared. MiRNA expression was analyzed by quantitative real-time PCR. The expression of miR-148a was significantly upregulated, and miR-320 downregulated in oxytocin-treated mammary cells as well as their secreted extracellular vesicles to the media, compared with untreated cells. MiR-148a was found to be upregulated, and miR-320 was downregulated in the human colostrum of exogenous oxytocin-treated mothers. Moreover, miR-320 was highly expressed compared with miR-148a in the colostrum of mothers that did not receive exogenous oxytocin. In contrast, in the milk of mothers who received exogenous oxytocin, the expression of miRNA-148-3p was highly expressed compared with miR-320. This study shows that oxytocin modulates the expression of main milk-derived miRNAs. Our findings provide a novel insight into oxytocin's role in milk composition by regulating miRNA expression. Our results implicate that oxytocin increases miRNA expression in mammary epithelial cells and human milk, affecting human milk composition and may contribute to further infant health.

Pressure assisted thermal pasteurization (PATP) of hypoallergenic and low protein ready-to-feed (RTF) infant formula fortified with bioactives: A novel approach

Infant Milk Formula (IMF) is an instant alternative to breastfeeding which is being investigated continuously to mimic the composition of human milk. Hypoallergenic IMF is recommended for infants who cannot tolerate cow milk due to allergy. Paediatric obesity resulted in burgeoning demand for low protein infant formula, especially in Asia. Beta-lactoglobulin (β-Lg), a major cow milk allergen to infants, is present in cow milk as 3–4 g/L, whereas, interestingly, it is absent in human milk. Besides, human milk contains Fe3+ binding lactoferrin (LF) and Ca2+ binding alpha-lactalbumin (α-Lac) about 10 and 3 times, respectively, higher than cow milk. Therefore, a mechanism to formulate a hypoallergenic IMF with low protein content could be the addition of LF and α-Lac and reducing β-Lg at the same time using an appropriate processing method. Hence, as a pragmatic approach, this study considered a pasteurized form of ready-to-feed (RTF) by applying Pressure Assisted Thermal Pasteurization (PATP) achieved from HPP of 600 MPa for 15 s applied at 57.1 °C to attain 72.3 °C after pressurization. In parallel, conventional HTST was also applied at 72 °C for both 15 and 30 s to compare PATP's effect. HTST and PATP retained >90% and > 75% LF respectively whereas PATP induced higher retention of α-Lac compared to HTST. However, HTST retained >60% β-Lg while PATP induced a high denaturation of β-Lg with 28% retention only. Moreover, both PATP and HTST induced around 5 log reduction of E. coli (ATCC 8739) in IMF. Therefore, the current investigation potentially indicates a route to develop a PATP-processed hypoallergenic and low protein RTF formula, a niche product.

Do Maternal Factors and Milk Expression Patterns Affect the Composition of Donor Human Milk?

A primary role of Human Milk Banks (HMBs) is to provide human milk (HM) for preterm infants and to support the mothers of these infants as they establish their own milk supply. A better understanding of the variation in the energy and macronutrients contents of donor human milk (DHM) potentiates targeted nutrition for preterm babies. Therefore, the aim of this study was to assess the variability of energy and macronutrients content in DHM and to investigate the impact of maternal factors and feeding practices on the nutritional value of DHM. The study involved 49 donors registered in the HMB in the Holy Family Hospital in Warsaw, Poland. Samples from each donor were pooled within a maximum of two weeks. The composition of DHM, including energy content, protein, fat, and carbohydrate concentrations, was analyzed using the Miris Human Milk Analyzer. The analyses were performed before the pasteurization process. The mean time of milk donation to HMB was 13.2 ± 6.0 weeks. There were no significant differences in energy and macronutrients contents of DHM in the beginning and at the end of milk donation to HMB, however, HM fat concentration was positively correlated with afternoon feedings (r = 0.289, p = 0.044). The method of feeding (breastfeeding vs. feeding only expressed milk) also did not impact the nutritional value of DHM. Future research for the DHM should include a further cross-sectional observational study with the collection of detailed donor information and characteristics of milk expression and feeding practices to further evaluate the pooling processes and the effect on DHM composition.

Relationship between traditional maternal diet pattern and breastmilk composition of rural lactating women during the first month postpartum in Shigatse, Tibet.

Maternal nutrition can influence the composition of human breastmilk by altering the components that are sensitive to maternal diet pattern. Traditional Tibetan maternal diet pattern among native rural lactating women possesses distinct characteristics due to its unique geographical environment and dietary habits. This study investigated maternal diet pattern and human breastmilk composition of Tibetan lactating women through different lactation stages during the first month postpartum in Shigatse. The results indicated that Tibetan maternal diet profile was apparently monotonous, mainly sufficient in Zanba, buttered tea, red meat, and fatty soup, yet insufficient in white meat, eggs, leafy vegetables, and fruits, leading to imperfect maternal nutritional intakes with high‐level carbohydrates and deficient proteins. Distinctions of maternal diet profiles in various degrees can be discovered upon different lactation stages, which brings multiple influences to the composition of human milk. There was significantly weak‐to‐medium correlation of protein contents between maternal diet intakes and human milk, while other macronutrients correlated insignificantly. Micronutrient constituents in human milk, involving functional unsaturated fatty acids and free essential amino acids, were also impacted by maternal diet intakes through different lactation stages. These results show that more systematic and profound research is requisite for the clarification and development of Tibetan maternal diet to offer more enhanced and individualized nutritional recommendations for Tibetan lactating women and infants.

Fatty acid composition of human breast milk across lactational stages in six representative cities in China from 2018 to 2019

To investigate the fatty acid composition in breast milk at different lactation stages in six representative cities of China. From January 2018 to December 2019, milk sampling of 690 healthy lactating mothers(full-term) in 5 lactation periods of 0-5 days, 10-14 days, 40-45 days, 200-240 days and 300-400 days was collected from 6 representative regions in China, with 23 cases of breast milk received in each lactation stage in each city. Mix it into one mixture, and make a total of 30 mixes. Determination of fatty acids in breast milk was conducted by gas chromatography-flame ionization detector. The contents of total fatty acids(TFA), saturated fatty acids(SFA), monounsaturated fatty acids(MUFA) and polyunsaturated fatty acids(PUFA) in breast milk increased with the progress of lactation and reached a relatively stable level after reaching a peak at 40-45 days. However, the composition ratio of SFA, MUFA and PUFA in TFA remained relatively stable from 0 to 400 days. The ratio of arachidonic to docosahexaenoic(AA/DHA) in breast milk from 0 to 400 days in the six cities ranged from 1.14 to 1.55, and there was no obvious trend of change in the whole lactation stage. The ratio of linoleic acid to alpha-linolenic acid(LA/ALA) in Chinese breast milk ranged from 3.84 to 18.94, showing significant regional variation. The content and composition of fatty acids in breast milk of six cities in China vary to a certain extent and show a dynamic change process with the passage of time of lactation.

Maternal dietary patterns are associated with human milk composition in Chinese lactating women

ObjectivesDietary patterns are a useful tool to study the impact of overall maternal diet on human milk (HM) composition beyond single foods or nutrients. The present study aimed to identify dietary patterns among Chinese lactating women and assess their associations with HM macronutrient composition. MethodsDietary intake data and HM samples were collected from 122 Chinese mothers at three to five study visits during the first 52 d postpartum. Dietary patterns were derived using principal component analysis. Cross-sectional associations of dietary patterns and HM macronutrients were assessed using multivariable linear regression models adjusted for total energy intake. All analyses were done separately for colostrum (postpartum days 0-7) and mature milk (postpartum days 8-52). ResultsFour dietary patterns were identified: high-in-animal-foods, high-in-eggs, high-in-plant-foods, and high-in-fruits. Compared with the lowest tertile (T1), participants in the highest tertile (T3) of the high-in-animal-foods and high-in-plant-foods patterns had lower protein (respectively, T3 − T1 = −1.09 g/100 mL, Ptrend = 0.002; T3 − T1 = −0.54 g/100 mL, Ptrend = 0.001) and higher fat (respectively, T3 − T1 = 0.86 g/100 mL, Ptrend = 0.040; T3 − T1 = 0.40 g/100 mL, Ptrend = 0.004) concentrations in colostrum. In contrast, in mature milk the high-in-animal-foods pattern was positively associated with carbohydrates (T3 − T1 = 0.53 g/100 mL, Ptrend = 0.008) and the high-in-plant-foods pattern was negatively associated with fat (T3 − T1 = −0.64 g/100 mL, Ptrend = 0.002). The high-in-eggs pattern was weakly positively associated with protein concentration in mature milk (T3 − T1 = 0.10 g/100 mL, Ptrend = 0.023). ConclusionsMaternal dietary patterns with high proportions of animal and plant-based foods were associated with higher fat and lower protein concentrations in colostrum. Different associations were found in mature milk. Dietary-pattern analysis provides an opportunity to characterize total diet and may be more predictive of HM composition than single foods or nutrients.

Macronutrient analysis of human milk and factors associated with its composition in mothers of preterm infants ≤ 32 weeks.

We conducted an exploratory longitudinal study to evaluate the macronutrient composition of human milk in mothers delivering very preterm infants ≤ 32 weeks over the first 4 weeks of lactation and the association of human milk composition with maternal and neonatal factors A total of 213 human milk samples collected in the morning between 8 am and 12 pm from 60 eligible mothers were analyzed on 7 (n = 60), 14 (n = 60), 21 (n = 52), and 28 (n = 41) days of lactation by infrared transmission spectroscopy. The true protein content decreased significantly over 4 weeks (mean difference (95% confidence interval)) (MD (95% CI)) week 1 and week 4 = 0.2 g (0.037 to 0.363, P = 0.009)). On the contrary, the mean fat and calorie content showed significant increase over time (MD (95% CI)) = - 1.03 g (- 1.719 to - 0.343, P = 0.001) and - 9.0 kcal/dl (- 15.170 to - 2.830, P = 0.001), respectively). There was no difference in the carbohydrate content of human milk over 4 weeks. Macronutrient composition was independent of maternal parity, mode of delivery, pre-pregnancy body mass index, umbilical artery Doppler flows, previous breast feeding experience, neonatal centile status, gestation, and infant's weight at birth. Multiple regression analysis of human milk composition with mother's dietary components showed no significant association. CONCLUSION : We conclude that in mothers who deliver very preterm infants ≤ 32 weeks, true protein content decreased, fat and calorie content increased, and carbohydrate content remained stable in human milk during first 4 weeks of lactation. Human milk macronutrient composition was independent of various maternal and neonatal factors including maternal body mass index and dietary intake. TRIAL REGISTRATION : CTRI/2017/02/007895 What is Known: • Preterm human milk has high temporal and inter-individual variation in the macronutrient composition. What is New: • In mothers who deliver very preterm infants < 32 weeks, true protein content decreases, fat and calorie content increases, and carbohydrate content remains stable in human milk during first 4 weeks of lactation. • Human milk macronutrient composition is independent of various maternal and neonatal factors including maternal body mass index and dietary intake.

Maternal Nutrition Status and Human Milk Composition of DHA and AA Fatty Acids in Breastfeeding Honduran Women

Dietary habits and maternal nutrition status are the most important modifiable factors that will determine the concentration of certain essential components and nutrients in Breast Milk (BM).The objectives were to estimate the nutritional status of Breastfeeding (BF) women in rural Honduras, identifying the main food sources that contribute to the consumption of EFA and its content in BM. The Honduran study was part of an international study with a sample (n=25) with children between 26 and 64 days of age. The consumption of food sources of Essential Fatty Acids (EFA) was evaluated with a frequency questionnaire. BMcomposition was analyzed using the dry drop method with Guthrie cards. 56% of mothers provided exclusive BF, 27% of mothers were overweightand 68% had excess body fat. The average monthly consumptionof marine foods was 1.44, 0.60 and 0.68 servings of fish, sardines and tuna, respectively. The average consumption of Docosahexaenoic Acid (DHA) and Arachidonic Acid (AA) was 0.05 g / day. The content of DHA, EPA and AA fatty acids in BM was 0.14, 0.01 and 0.4% respectively. The amount of DHA and AA in the BF women is well below the median values of a global reference distribution.

Human Milk and Brain Development in Infants

Human milk is considered the most advantageous source of nourishment for infants. Even though there is no ideal composition of human milk, it still contains a unique combination of components that contribute to brain development. The aim of this review is to provide an overview on the possible correlation of human milk with the neurodevelopment of infants, with a special emphasis on myelination and epigenetic modifications. Research in human milk is a rapidly expanding field and cutting-edge technologies might contribute to identify specific mechanisms underlying the beneficial effects on human milk on neurodevelopment.

Dietary Patterns During Lactation and Human Milk Composition and Quantity: A NESR Systematic Review

ObjectivesTo inform the Dietary Guidelines for Americans, 2020–2025, the USDA and HHS identified important public health questions to be examined by the 2020 Dietary Guidelines Advisory Committee. The Committee conducted a systematic review with support from the USDA’s Nutrition Evidence Systematic Review (NESR) team to answer the question: What is the relationship between dietary patterns consumed during lactation and human milk composition and quantity? MethodsThe Committee developed protocols to describe how they would use NESR’s SR methodology to examine the evidence related to dietary patterns (DP) during lactation and human milk (HM). NESR librarians conducted a literature search and NESR analysts dual-screened the results using pre-defined inclusion and exclusion criteria to identify articles published between 2000 and 2019. NESR analysts extracted data from and assessed the risk of bias of included studies. The Committee synthesized the evidence, developed conclusion statements, and graded the strength of the evidence. ResultsThis systematic review included 7 articles. Three articles from 2 cross-sectional studies examined DP and HM, while 4 articles from 3 randomized controlled trials examined diets based on macronutrient distributions and HM. The body of evidence was limited by small sample sizes, risk of bias concerns, heterogeneous methods, and study populations with limited racial/ethnic and socioeconomic diversity. ConclusionsLimited evidence suggests that maternal consumption of diets higher in fat (>35% fat) and lower in carbohydrate during lactation is related to higher total fat in HM collected in the maternal postprandial period. Limited evidence suggests that certain maternal DP during lactation, including diets based on macronutrient distributions, are related to the relative proportions of saturated fat and monounsaturated fatty acids in HM, and of polyunsaturated fatty acids in HM collected in the maternal postprandial period. Insufficient or no evidence was available to assess the association between DP during lactation and HM quantity, as well as total protein, water- and fat-soluble vitamins, minerals, human milk oligosaccharides, and bioactive proteins in HM. Funding SourcesUSDA, Food and Nutrition Service, Center for Nutrition Policy and Promotion.

A Mediterranean Meal Plan Modulates Human Milk Composition in Women With Obesity

ObjectivesHuman milk (HM) is impacted by both maternal obesity and diet. HM from women with obesity has higher fat, leptin and insulin concentrations. Additionally, maternal dietary fat intake is associated with increased HM fat content. The objective of this study was to determine the impact of a Mediterranean meal plan on the composition of HM from women with obesity. MethodsIn this pilot study, thirteen women with obesity (body mass index (BMI) ≥ 30 kg/m2) enrolled at five months post-partum and followed a provided Mediterranean meal plan focused on reducing fat intake and increasing unsaturated fat and fiber intake for four weeks. Participants’ diet was assessed using Nutrition Data System for Research. HM was collected at baseline and after the 4-week intervention and the concentrations of metabolites, hormones and cytokines were assayed. Wilcoxon signed-rank tests and analysis of variance were used to assess changes in participant diet and HM composition. Summary statistics are presented as mean ± standard deviation. ResultsThe participants’ Healthy Eating Index Score, a measure of diet quality, significantly improved (38.3 ± 5.13 vs. 78.2 ± 6.75, p < 0.001) and total fat intake was significantly lower (99.6 ± 23.3 g vs. 66.9 ± 12.0 g/day, p < 0.001) after the intervention. Human milk leptin (694 ± 464 pg/ml vs. 437 ± 324 pg/ml, p = 0.007) and tumor necrosis factor α (0.515 ± 0.267 pg/ml vs. 0.310 ± 0.127 pg/ml, p = 0.010) concentrations were lower post intervention, whereas HM macronutrient composition was unchanged. The concentrations of several individual human milk oligosaccharides (HMO) and total HMOs (7720 ± 797 nmol/ml vs. 6986 ± 940 nmol/ml, p = 0.049), as well as HM tyrosine concentration (18.2 ± 6.16 nmol/ml vs. 14.5 ± 4.69 nmol/ml, p = 0.005) were significantly lower post intervention. ConclusionsThe composition of HM from women with obesity can be modulated by short-term adherence to a Mediterranean meal pattern. These findings merit further studies that use longer interventions and examine the impact of any changes in HM composition on infant growth and development. Modifying HM composition via a dietary intervention may provide a novel strategy to promote child development and health. Funding SourcesUSDA ARS #6026-51,000-010-05S and #6026-51,000-012-06S, NIH/NIDDK R01DK107516, Arkansas Children’s Research Institute/Arkansas Biosciences Institute GR037121.

Reduction in Maternal Energy Intake during Lactation Decreased Maternal Body Weight and Concentrations of Leptin, Insulin and Adiponectin in Human Milk without Affecting Milk Production, Milk Macronutrient Composition or Infant Growth.

Maternal diet has the potential to affect human milk (HM) composition, but very few studies have directly assessed the effect of maternal diets on HM composition. The primary aim of this study was to assess the effect of improving dietary quality in lactating women over 2 weeks on the concentrations of macronutrients and metabolic hormones in HM. The secondary aims were to assess the impact of the dietary intervention on 24 h milk production, maternal body composition and infant growth. Fifteen women completed a 1-week baseline period followed by a 2-week dietary intervention phase targeted towards reducing fat and sugar intake. Maternal anthropometric and body composition and infant growth measurements were performed weekly. Total 24 h milk production was measured before and after the dietary intervention, and HM samples were collected daily. Maternal intakes of energy (−33%), carbohydrate (−22%), sugar (−29%), fat (−54%) and saturated fat (−63%) were significantly reduced during the dietary intervention. HM insulin, leptin and adiponectin concentrations were 10–25% lower at the end of the dietary intervention, but HM concentrations of macronutrients were unaffected. Maternal body weight (−1.8%) and fat mass (−6.3%) were significantly reduced at the end of the dietary intervention, but there were no effects on 24 h milk production or infant growth. These results suggest that reducing maternal energy, carbohydrate, fat and sugar intake over a 2-week period is associated with significant reductions in HM insulin, leptin and adiponectin concentrations. These changes may be secondary to decreases in maternal weight and fat mass. The limited studies to date that have investigated the association between metabolic hormone concentrations in HM and infant growth raise the possibility that the changes in HM composition observed in the current study could impact infant growth and adiposity, but further studies are required to confirm this hypothesis.

Variation in Human Milk Composition Is Related to Differences in Milk and Infant Fecal Microbial Communities.

Previously published data from our group and others demonstrate that human milk oligosaccharide (HMOs), as well as milk and infant fecal microbial profiles, vary by geography. However, little is known about the geographical variation of other milk-borne factors, such as lactose and protein, as well as the associations among these factors and microbial community structures in milk and infant feces. Here, we characterized and contrasted concentrations of milk-borne lactose, protein, and HMOs, and examined their associations with milk and infant fecal microbiomes in samples collected in 11 geographically diverse sites. Although geographical site was strongly associated with milk and infant fecal microbiomes, both sample types assorted into a smaller number of community state types based on shared microbial profiles. Similar to HMOs, concentrations of lactose and protein also varied by geography. Concentrations of HMOs, lactose, and protein were associated with differences in the microbial community structures of milk and infant feces and in the abundance of specific taxa. Taken together, these data suggest that the composition of human milk, even when produced by relatively healthy women, differs based on geographical boundaries and that concentrations of HMOs, lactose, and protein in milk are related to variation in milk and infant fecal microbial communities.

Dietary Patterns of Breastfeeding Mothers and Human Milk Composition: Data from the Italian MEDIDIET Study.

(1) Background: Several studies have reported associations between maternal diet in terms of single foods or nutrients and human milk compounds, while the overall role of maternal diet and related dietary patterns has rarely been investigated. (2) Methods: Between 2012 and 2014, we enrolled 300 healthy Italian mothers, who exclusively breastfed their infant. During a hospital visit at 6 weeks postpartum, a sample of freshly expressed foremilk was collected and information on maternal dietary habits in the postpartum period was obtained through an interviewer-administered food frequency questionnaire. We applied principal component factor analysis to selected nutrients in order to identify maternal dietary patterns, and assessed correlations in human milk macronutrients and fatty acids across levels of dietary patterns. (3) Results: Five dietary patterns were identified, named “Vitamins, minerals and fibre”, “Proteins and fatty acids with legs”, “Fatty acids with fins”, “Fatty acids with leaves”, “Starch and vegetable proteins”. These dietary patterns were correlated with some milk components, namely fatty acids, and in particular ω-3 and its subcomponents. (4) Conclusions: This study showed that overall maternal dietary habits during breastfeeding may influence human milk composition, suggesting the importance of adequate maternal nutrition during lactation not only for the mother herself but also to provide the infant with milk containing adequate amount and quality of nutrients for a balanced nutrition.

Daily variation of macronutrient concentrations in mature human milk over 3 weeks

Human milk (HM) composition is known to be highly variable, both between individuals and across the duration of lactation. It is less clear, however, to what extent fat, lactose and protein concentrations in HM change daily over shorter time periods in mature HM, and no studies have evaluated this to date. The aim of this study was to systematically assess and compare HM macronutrient concentrations in samples collected at different times of day, from left and right breasts and daily across a 3-week period in the same woman. Fifteen lactating women (1.6–4.9 months postpartum) collected daily pre-feed HM samples from both breasts each morning for 21 consecutive days and completed intensive sampling once a week (morning, afternoon and evening samples) during this period. Concentrations of fat, protein and lactose in HM did not differ according to time of day, day of week or breast used for collection. The results of this study suggest that pre-feed samples collected at any point across a 3-week period and from either the left or right breast provide comparable measures of fat, protein and lactose concentrations in mature HM, in pragmatic studies where women are collecting their own HM samples.Clinical trial registration: Australian New Zealand Clinical Trials Registry (ACTRN12619000606189).

What Are the Maternal Factors that Potentially Intervenes in the Nutritional Composition of Human Milk?

Background: To evaluate the potential factors associated with the nutritional composition of human milk of puerperal women. Methods: cross-sectional study, conducted between March 2016 and August 2017, with 107 women, selected in a Tertiary Health Care Tertiary Health Facility of the Unified Health System (SUS) in the Municipality of Rio de Janeiro. Data were collected two months after delivery. The dependent variable of the study was the nutritional composition of human milk. We divided the independent variables into hierarchical levels: distal (age, schooling, parity and pregestational nutritional status), intermediate (number of prenatal visits and gestational weight gain) and proximal (alcohol consumption, smoking, diabetes mellitus and hypertension). For data analysis, we applied the multiple linear regression, centered on the hierarchical model. Only the variables associated with the nutritional composition of breast milk remained in the final model at a 5% level of significance. Results: The nutritional composition of human milk yielded by women with pregestational overweight, smokers and hypertensive had higher amounts of lipids and energy. Conversely, women with gestational weight gain below the recommended had lower amounts of these components. Conclusion: The evaluation of factors associated with the nutritional composition of human milk is extremely important to assist post-partum care practices. In this study, we observed that lipid and energy contents were associated to pregestational nutritional status, gestational weight gain, smoking and hypertension.

The need to study human milk as a biological system

ABSTRACTCritical advancement is needed in the study of human milk as a biological system that intersects and interacts with myriad internal (maternal biology) and external (diet, environment, infections) factors and its plethora of influences on the developing infant. Human-milk composition and its resulting biological function is more than the sum of its parts. Our failure to fully understand this biology in a large part contributes to why the duration of exclusive breastfeeding remains an unsettled science (if not policy). Our current understanding of human-milk composition and its individual components and their functions fails to fully recognize the importance of the chronobiology and systems biology of human milk in the context of milk synthesis, optimal timing and duration of feeding, and period of lactation. The overly simplistic, but common, approach to analyzing single, mostly nutritive components of human milk is insufficient to understand the contribution of either individual components or the matrix within which they exist to both maternal and child health. There is a need for a shift in the conceptual approach to studying human milk to improve strategies and interventions to support better lactation, breastfeeding, and the full range of infant feeding practices, particularly for women and infants living in undernourished and infectious environments. Recent technological advances have led to a rising movement towards advancing the science of human-milk biology. Herein, we describe the rationale and critical need for unveiling the multifunctionality of the various nutritional, nonnutritional, immune, and biological signaling pathways of the components in human milk that drive system development and maturation, growth, and development in the very early postnatal period of life. We provide a vision and conceptual framework for a research strategy and agenda to change the field of human-milk biology with implications for global policy, innovation, and interventions.

The Influence of Holder Pasteurization on the Diversity of the Human Milk Bacterial Microbiota Using High-Throughput DNA Sequencing.

Human milk is the best food for infants; however, when breastfeeding is not possible, pasteurized milk from human milk banks is the best alternative. Little has been reported about variations in the bacterial microbiota composition of human milk after pasteurization. To characterize and compare the bacterial microbiota composition and diversity within human milk among Mexican mothers before and after the Holder pasteurization process. A cross-sectional, observational, and comparative design was used. The effect of the pasteurization process on the bacterial composition and diversity of human milk samples of donors (N = 42) from a public milk bank was assessed before and after pasteurization by high throughput deoxyribonucleic acid sequencing of V3-16S rRNA gene libraries. Sequencing data were examined using the Quantitative Insights into Microbial Ecology software and Phyloseq in R environment. A varied community of bacteria was found in both raw and pasteurized human milk. The bacterial diversity of the milk samples was increased by the pasteurization, where some thermoduric bacteria of the phyla Proteobacteria, Firmicutes, and Actinobacteria were more abundant. The source tracker analysis indicated that at most 1.0% of bacteria may have come from another source, showing the safety of the process used to treat milk samples. The pasteurization process increased the bacterial diversity. We selected taxa capable of surviving the process, which could proliferate after the treatment without being a risk for infants.