Breast milk macro- and micronutrient composition in lactating mothers from suburban and urban Shanghai

Determination of Minor and Trace Elements in Breast Milk of Lactating Mothers in Early Lactation from Tehran, Iran Using Neutron Activation Analysis Method

This study aimed to evaluate the concentrations of both essential and non-essential elements in the breast milk of lactating mothers from Tehran, Iran, during the colostrum period. Neutron activation analysis (NAA) was used to measure the element concentrations. Additionally, the study assessed how these element concentrations were influenced by maternal factors such as age and economic status. Breast milk samples were collected from 95 lactating mothers, aged 18 to 41, during the early lactation phase, specifically within the colostrum period (2-7 days postpartum). The colostrum milk samples were freeze-dried, powdered, and irradiated at the Tehran Research Reactor for neutron activation analysis (NAA). This method was used to measure the concentrations of essential elements-calcium (Ca), potassium (K), sodium (Na), chlorine (Cl), and iodine (I)-as well as non-essential elements-aluminum (Al), bromine (Br), and rubidium (Rb). Descriptive statistics, including mean, median, maximum, minimum, and standard deviation, were calculated for each element. Statistical analyses, such as Pearson's correlation, were performed to assess relationships between the concentrations of various elements. Additionally, t-tests and p-values were employed to evaluate differences in element levels across maternal age groups (17-34 years vs. 35-45 years) and economic status (high/middle vs. low). The mean concentrations of the elements in dry breast milk powder samples were: Al = 6.9 mg/kg, Br = 11.9 mg/kg, Ca = 2.757 mg/g, Cl = 7.836 mg/g, I = 1.22 mg/kg, K = 5.853 mg/g, Na = 4.932 mg/g, and Rb = 3.69 mg/kg. Significant correlations were found between element pairs, such as Na-Cl, Br-Cl, Na-Br, Rb-K, and I-Cl. Maternal age significantly influenced bromine concentrations, with older mothers showing 22% higher Br levels (p = 0.038), while calcium levels were 15% lower but not statistically significant (p = 0.20). Maternal economic status significantly impacted calcium and potassium concentrations, with higher levels observed in mothers from better economic conditions (p = 0.02 and p = 0.025, respectively). This study highlights the elemental composition of breast milk samples of lactating mothers in Tehran and shows that maternal factors, such as age and economic status, can significantly influence the concentrations of specific elements in breast milk.

Composition and Antioxidant Status of Human Milk of Women Living in Bydgoszcz (Poland)

OBJECTIVES

The aim of this study was to compare cortisol concentrations, nutritional composition, and the antioxidant status of human milk of women living in Bydgoszcz (Poland), taking into account maternal factors (fertility, area of residence, economic activity, and breastfeeding period).

METHODS

The basic composition of human milk was evaluated using the MIRIS HMATM analyzer. The level of cortisol was determined by the enzyme-linked immunosorbent method. In order to determine the antioxidant activity, the DPPH radical method was used.

RESULTS

It was observed that the concentration of cortisol in human milk in the group of women living in the city center was higher compared to the milk of women living on the outskirts of the city. In the group of women breastfeeding from 3 to 5 weeks after childbirth, the concentration of cortisol in milk was higher compared to the group of women breastfeeding less than 12 months of age and compared to the group of women lactating over 12 months of age. The antioxidant status of human milk was highest in the group of professionally active women and in the group of breastfeeding women from 3 to 5 weeks after childbirth. The basic composition and the caloric value of human milk differed statistically significantly in the study groups.

CONCLUSIONS

Based on this study, it can be concluded that the composition and antioxidant status of human milk depends on maternal factors (fertility, professional activity, area of residence, and breastfeeding period). Higher cortisol concentrations in breast milk are probably determined by the area of residence (city center and associated higher noise/sound and stress levels) and lactation period (hormonal imbalance, fatigue, and postpartum period). Milk from economically active women shows greater protection against reactive oxygen species compared to milk from inactive women, protecting against the occurrence of diseases of civilization. Milk from breastfeeding women over 12 months of age also shows protection against reactive oxygen species, despite the fact that the highest level of antioxidant status of human milk occurs in the initial period of lactation.

Longitudinal Changes in Human Milk Minerals and Vitamins in the Chinese Population: A Scoping Review

This scoping review aims to investigate longitudinal changes in minerals and vitamins concentrations in human milk among the Chinese population. Following the PRISMA-ScR guidelines, a comprehensive and systematic literature search was conducted using both English and Chinese databases. Data were extracted and categorized into six defined lactation stages. We found that the concentration of most minerals decreased throughout the lactation period, although calcium (Ca) and magnesium (Mg) fluctuated slightly across lactation periods. Fat-soluble vitamins also showed a decline throughout the lactation period, while water-soluble vitamins exhibited an increasing trend. However, folic acid, biotin, and pantothenic acid demonstrated a downward trend. Overall, this review has identified the longitudinal changes in minerals and vitamins concentrations in human milk among the Chinese population. In order to conduct a more in-depth examination of maternal characteristics and nutritional factors of the composition of human milk, it is recommended to utilize standardized protocols for the collection and analysis of human milk samples.

Scientific opinion on the tolerable upper intake level for manganese

Following a request from the European Commission (EC), the EFSA Panel on Nutrition, Novel Foods and Food Allergens (NDA) was asked to deliver a scientific opinion on the tolerable upper intake level (UL) for manganese. Systematic reviews of the literature of human and animal data were conducted to assess evidence regarding excess manganese intake (including authorised manganese salts) and the priority adverse health effect, i.e. manganese-induced neurotoxicity. Available human and animal studies support neurotoxicity as a critical effect, however, data are not sufficient and suitable to characterise a dose-response relationship and identify a reference point for manganese-induced neurotoxicity. In the absence of adequate data to establish an UL, estimated background dietary intakes (i.e. manganese intakes from natural dietary sources only) observed among high consumers (95th percentile) were used to provide an indication of the highest level of intake where there is reasonable confidence on the absence of adverse effects. A safe level of intake of 8 mg/day was established for adults ≥ 18 years (including pregnant and lactating women) and ranged between 2 and 7 mg/day for other population groups. The application of the safe level of intake is more limited than an UL because the intake level at which the risk of adverse effects starts to increase is not defined.

Association between adherence to a low carbohydrate dietary (LCD) pattern with breast milk characteristics and oxidative markers in infants' urine: a cross-sectional study

BACKGROUND

Breast milk (BM) is a dynamic fluid that varies over time and between women. The variations in BM components are most likely associated with maternal diet quality. This study aimed to assess adherence to a low carbohydrate dietary (LCD) pattern with oxidative stress markers of BM characteristics and infants' urine.

MATERIALS AND METHODS

In this cross-sectional study 350 breastfeeding mothers and their infants were recruited. BM samples were collected from mothers, and urine specimens were obtained from each infant. To evaluate LCD scores, subjects were divided into 10 deciles according to the percent of energy obtained from carbohydrates, proteins, and fats. Determination of total antioxidant activity was conducted using the ferric reducing antioxidant power (FRAP), 2, 2'-diphenyl-1-picrylhydrazyl (DPPH), thiobarbituric acid reactive substances (TBARs), and Ellman's assay. Biochemical assays of samples including calcium, total protein, and triglyceride level were also performed using commercial kits.

RESULTS

Participants with the greatest LCD pattern adherence were placed into the last quartile (Q4), and those with the minimum LCD were in the first quartile (Q1). Individuals in the highest LCD quartile had significantly higher levels of milk FRAP, thiol, and protein, as well as infant urinary FRAP and lower milk MDA levels than those in the lowest quartile. Multivariate linear regression analyses indicated that higher score of the LCD pattern was associated with a higher level of milk thiol, protein, and lower level of milk MDA (p < 0.05).

CONCLUSION

Our findings show that adherence to a LCD, as defined by a low level of carbohydrates in daily food intake, is linked with improved BM quality and markers of oxidative stress in infant urine.

Effect of Different Dietary Patterns on Macronutrient Composition in Human Breast Milk: A Systematic Review and Meta-Analysis

The aim of this meta-analysis was to systematically review the relationships between lactation diet and the composition of mature breast milk through screening multiple databases and gray literatures, with priority given to quantitative articles published in Chinese and English. We identified 27 cross-sectional studies that included 4355 lactating women. According to these data, dietary patterns were categorized into four patterns based on the fat and protein energy supplying ratio, including rational-fat and rational-protein dietary (RR), high-fat and high-protein dietary (HH), rational-fat and high-protein dietary (RH), and high-fat and rational-protein dietary (HR). The results showed the fat content in mature milk was increased with increments of fat intake, while both the protein and lactose contents in mature milk did not increase with their intakes for lactating mothers. Among these four dietary patterns, the energy ratio of macronutrients in human milk at the RR was the closest to the estimated energy ratio for infants aged 0-6 M. In conclusion, our study represents that the rational dietary pattern should be advocated, and the irrational dietary patterns, especially high-fat and high-protein dietary patterns, should be avoided during lactation stage.

Human Milk Lipid Profiles around the World: A Systematic Review and Meta-Analysis

Reported breast milk lipid concentrations may vary with geographical region, postnatal age, and year of sample collection. In this review, we summarized data on the concentrations of total fat, total phospholipids, cholesterol, and fatty acids in human milk worldwide and their variation according to lactation stage, study area, and sample collection year. A systematic literature search was performed using the PubMed, Embase, Web of Science, and Medline databases for English-language papers and Wanfang and China National Knowledge Infrastructure databases for Chinese-language papers. A total of 186 studies evaluating the human milk lipid profiles were included. According to random-effects models based on worldwide data, the summarized means (95% CIs) as percentages of total fat were 42.2% (41.1%, 43.3%) for SFAs, 36.6% (35.6%, 37.5%) for MUFAs, and 21.0% (19.3%, 22.7%) for PUFAs. However, the study heterogeneity was high for most types of fatty acids (I2 > 99%). Human milk from Western countries had higher concentrations of MUFAs and 18:1n-9 (ω-9), but lower concentrations of PUFAs, 18:2n-6, 20:4n-6, 18:3n-3, 20:5n-3, 22:6n-3, and total n-6 PUFA compared with those from non-Western countries (P < 0.001-0.011). Significant lactation stage differences were observed for total fat and some individual fatty acids. The concentrations of SFAs and 16:0 were significantly negatively correlated with sampling year (P < 0.001-0.028). In contrast, a significant positive correlation between the concentrations of 18:2n-6 and 18:3n-3 and sampling year was observed (P < 0.001-0.035). Our results suggest that the pooling of data on human milk lipid profiles in different studies should be done with caution due to the high between-study heterogeneity. The concentration of lipids, including total fat, cholesterol, and specific fatty acids, differs in human milk according to lactation stage, geographical region, and year of sample collection.

Maternal dietary intake, nutritional status and macronutrient composition of human breast milk: systematic review

Human breast milk (BM) is the best source of nutrition in early life, particularly during the first 6 months. Nevertheless, human BM composition is variable, and more insight in the exact factors contributing to this variability is warranted. In this review, we explored the impact of maternal dietary intake and nutritional status (e.g. anthropometric measures, BMI, bioimpedance) on human milk macronutrient composition. PubMed, Scopus and Cochrane were systematically searched till November 2019. In total, 4946 publications underwent title-abstract screening; 101 publications underwent full-text screening. Eventually, fifty publications were included in this review, investigating either associations between maternal dietary intake (n 29) and/or maternal nutritional status (n 29), and macronutrient composition of human BM. Reported energy composition ranged from 213 to 301 kJ/100 ml, and 67 % and 54 % of the studies reported associations between with maternal nutritional intake and status, respectively. Protein content ranged from 0·8 to 3·3 g/100 ml, and four studies suggested a negative association with nutritional status. Fat content ranged from 2·1 to 9·8 g/100 ml, and 68 % of the studies reported positive associations with nutritional status. Carbohydrate content ranged from 5·8 to 7·5 g/100 ml, and 67 % of the included studies did not report an association between intake and status. Literature investigating associations of maternal dietary intake and nutrition status with BM composition of macronutrients and energy content is diversified, both in terms of used methodology and results. Further studies using well-defined and standard parameters are essential to aid the formulation of scientific recommendations.

Human Milk Concentrations of Minerals, Essential and Toxic Trace Elements and Association with Selective Medical, Social, Demographic and Environmental Factors

This study aims to quantify concentrations of minerals and trace elements in human milk (HM) and infant formula (IF) and evaluate associations with medical, social, environmental, and demographic variables. A prospective, case series study of 170 nursing mothers was made. HM samples were obtained from full-term (colostrum, intermediate and mature HM) and preterm (mature HM) mothers. Variables of interest were assessed by a questionnaire. For comparison, IF samples (n = 30) were analyzed in a cross-sectional study. Concentrations of 35 minerals, essential and toxic trace elements were quantified, 5 for the first time: thallium in HM and IF; strontium in preterm HM; and gallium, lithium and uranium in IF. In preterm and full-term HM, levels of selenium (p < 0.001) were significantly lower than recommended and were associated with low birth weight (p < 0.002). Cesium and strontium concentrations were significantly higher than recommended (p < 0.001). Associations were observed between arsenic and residence in an urban area (p = 0.013), and between lead and smoking (p = 0.024) and well-water consumption (p = 0.046). In IF, aluminum, vanadium, and uranium levels were higher than in HM (p < 0.001); uranium, quantified for the first time, was 100 times higher in all types of IF than in HM. Our results indicate that concentrations of most trace elements were within internationally accepted ranges for HM and IF. However, preterm infants are at increased risk of nutritional deficiencies and toxicity. IF manufacturers should reduce the content of toxic trace elements.

Estimating daily intakes of manganese due to breast milk, infant formulas, or young child nutritional beverages in the United States and France: Comparison to sufficiency and toxicity thresholds

BACKGROUND

Although manganese (Mn) is an essential nutrient, recent research has revealed that excess Mn in early childhood may have adverse effects on neurodevelopment.

METHODS

We estimated daily total Mn intake due to breast milk at average body weights by reviewing reported concentrations of breast milk Mn and measurements of body weight and breast milk intake at 3 weeks, 4.25 months, 7 months, and 18 months. We compared these figures to the Mn content measured in 44 infant, follow-up, and toddler formulas purchased in the United States and France. We calculated Mn content of formula products made with ultra-trace elemental analysis grade water (0 μg Mn/L) and with water containing 250 μg Mn/L, a concentration which is relatively high but less than the World Health Organization Health-based value of 400 μg Mn/L or the United States Environmental Protection Agency Health Advisory of 350 μg Mn/L.

RESULTS

Estimated mean daily Mn intake from breast milk ranged from 1.2 μg Mn/kg/day (3 weeks) to 0.16 μg Mn/kg/day (18 months), with the highest intakes at the youngest age stage we considered, 3 weeks. Estimated daily Mn intake from formula products reconstituted with 0 μg Mn/L water ranged from 130 μg Mn/kg/day (3 weeks) to 4.8 μg Mn/kg/day (18 months) with the highest intakes at 3 weeks. Formula products provided 28-520 times greater than the mean daily intake of Mn from breast milk for the 4 age stages that we considered. Estimated daily Mn intake from formula products reconstituted with water containing 250 μg Mn/L ranged from 12 μg Mn/kg/day to 170 μg Mn/kg/day, which exceeds the United States Environmental Protection Agency Reference Dose of 140 μg Mn/kg/day for adults.

CONCLUSIONS

Mn deficiency is highly unlikely with exclusive breast milk or infant formula feeding, but established tolerable daily intake levels for Mn may be surpassed by some of these products when following labeled instructions.

Child acceptability of a novel provitamin A carotenoid, iron and zinc-rich complementary food blend prepared from pumpkin and common bean in Uganda: a randomised control trial

BACKGROUND

Ugandan children are fed homemade complementary foods (CFs) which are usually deficient in vitamin A, iron and zinc. Novel homemade CFs rich in vitamin A, iron and zinc need to be developed, and assessed for their acceptability among target children.

OBJECTIVE

Homemade provitamin A carotenoids (PVACs), iron and zinc-rich complementary food (CF), common bean pumpkin blend (BPB) formulated from pumpkin (Sweet cream) and common bean (Obwelu) and PVAC-rich pumpkin blend (PB) from Sweet cream were prepared by expert peer mothers. This study compared child acceptability of BPB and PB (control).

METHODS

The crossover acceptability study randomly assigned Ugandan children 6 to 24 months old to either receive 100 g of BPB (n = 35) or 100 g of PB (n = 35) on day one. After a washout period of one day, children crossed over to receive either BPB (n = 35) or PB (n = 35). The amount of CF consumed, duration of consumption, and micronutrient intake were assessed. The CF was acceptable if children consumed ≥50 g (50%) of served food (100 g). A paired t-test was used to determine the mean differences within participants between BPB and PB. The level of statistical significant difference was set at a probability value of 5% (p = 0.05).

RESULTS

The mean consumption of BPB and PB was 53.9 g and 54.4 g, respectively. The mean duration for consumption of BPB and PB was 20.6 and 20.3 min, respectively. There was no significant difference in the amounts consumed, and duration of consumption in BPB and PB (p > 0.05). The mean intake of vitamin A was significantly higher (p < 0.00001) in PB (152.5 μgRAE) compared to BPB (100.9 μgRAE). The mean iron intake was significantly higher in BPB (1.1 mg) (p < 0.00001) compared to PB (0.3 mg). Furthermore, zinc intake was significantly higher (p < 0.00001) in BPB (0.58 mg) compared to PB (0.13 mg).

CONCLUSION

A homemade complementary food, BPB, made from locally available common bean and pumpkin is rich in PVACs, iron and zinc and is acceptable to children in the age range of complementary feeding in Uganda.

TRIAL REGISTRATION

Pan African Clinical Trials Registry www.pactr.org as PACTR202002576768667 . Retrospectively registered. Date of registration: 29/January/2020.

Longitudinal Changes in Crude Protein and Amino Acids in Human Milk in Chinese Population: A Systematic Review

OBJECTIVE

More than 20% of the world population live in China, which has made significant achievement in human milk research. Part of the data that were published in Chinese were, however, unavailable to non-Chinese speakers. There was also no comprehensive overview of crude protein and amino acid levels in human milk in Chinese population. This systematic review aimed to compile the data on human milk crude protein and amino acid levels in Chinese population.

METHODS

After searching for and screening original research articles in both English and Chinese, 23 published from 1987 to 2019 were identified (18 in Chinese and 5 in English). The data were pooled into 9 defined lactation stages.

RESULTS

Crude protein and amino acids (protein bound plus nonprotein bound) concentrations gradually decreased during the first 60 postpartum days and remained relatively static thereafter. The concentrations and dynamic change of crude protein and amino acids were similar to those in other populations. By contrast, the longitudinal changes in free amino acids (nonprotein bound) were less clear due to the limited data available. Several common weaknesses were identified in these studies.

CONCLUSIONS

Our study represented the most comprehensive overview on crude protein and amino acid concentrations in human milk in Chinese population, and enhanced the knowledge of protein and amino acid intakes and requirements by Chinese infants.

Caregiver Perceptions and Acceptability of a Provitamin A Carotenoid, Iron and Zinc Rich Complementary Food Blend Prepared from Common Bean and Pumpkin in Rural Uganda

Ugandan children are vulnerable to vitamin A deficiency (VAD), iron deficiency (ID) and zinc deficiency (ZnD) because they are fed on complementary foods (CFs) low in vitamin A, iron and zinc. This study developed a novel provitamin A carotenoid (PVAC), iron and zinc rich common bean pumpkin blend (BPB) complementary food (CF) from locally available pumpkin and common bean in Uganda and aimed to determine its acceptance, compared to a control pumpkin blend (PB). Seventy caregivers participated in the study. The sensory attributes (taste, colour, aroma, texture and general acceptability) of BPB and PB were rated using a five-point facial hedonic scale (1 = very bad, 2 = bad, 3 = neutral, 4 = good, 5 = very good). Focus group discussions (FGDs) were conducted to assess the perceptions of caregivers about the BPB. The chi square test was used to detect the proportion difference for each sensory attribute between BPB and PB, whilst FGD data were analysed by thematic analysis. A proportion of 64% to 96% of the caregivers rated both BPB and PB as acceptable (good to very good) for all the sensory attributes. There was no significant difference in caregiver acceptability for all attributes between BPB and PB (p > 0.05). Caregivers had positive perceptions about the taste, texture, aroma and colour of the BPB. Caregivers were keen to know the specific varieties of common bean and pumpkin used to formulate the PVAC, iron and zinc rich BPB. In conclusion, BPB was acceptable to caregivers, and they were interested to know how to prepare and use it as a CF.

Comparison of Changes in Breast Milk Macronutrient Content During the First Month in Preterm and Term Infants

Purpose: This study aims to achieve a better understanding of the trend of maternal milk macronutrient levels by analyzing protein, lipid, carbohydrate, and energy content of the breast milk and investigate the possible confounders of macronutrient content during the first 4 weeks of lactation to meet the specific needs of babies, guide optimum fortification of maternal milk. Patients and Methods: Breast milk from 39 mothers who had delivered preterm infants and 21 mothers of term infants were collected longitudinally for the first 4 weeks of lactation. Fresh milk samples were obtained on day 3, 7, 14, and 28 of lactation. The samples are analyzed using mid-infrared milk analyzer (MIRIS Human Milk Analyzer, HMA; Miris AB, Uppsala, Sweden). Results: Colostral milk protein concentrations of mothers of both preterm and term infants were significantly higher and the protein content of the samples decreased in time, according to the week of lactation during the study period. In contrast, fat, carbohydrate, and energy content were lowest in the colostral milk in both groups. When preterm and term milks were compared, fat and carbohydrate levels on 28th day and energy levels on 14th and 28th days were significantly higher in term milks, whereas no difference in protein contents were observed between the two groups on each time period. Mode of delivery was found to have statistically significant correlation with protein content of the milk. Conclusion: This longitudinal study revealed significant changes in analyzed macronutrient contents of mother's milk over the first 4 week period.

Dietary Manganese Exposure in the Adult Population in Germany-What Does it Mean in Relation to Health Risks?

Manganese is both an essential nutrient and a potential neurotoxicant. Therefore, the question arises whether the dietary manganese intake in the German population is on the low or high side. Results from a pilot total diet study in Germany presented here reveal that the average dietary manganese intake in the general population in Germany aged 14-80 years is about 2.8 mg day^-1 for a person of 70 kg body weight. This exposure level is within the intake range of 2-5 mg per person and day as recommended by the societies for nutrition in Germany, Austria, and Switzerland. No information on the dietary exposure of children in Germany can be provided so far. Although reliable information on health effects related to oral manganese exposure is limited, there is no indication from the literature that these dietary intake levels are associated with adverse health effects either by manganese deficiency or excess. However, there is limited evidence that manganese taken up as a highly bioavailable bolus, for example, uptake via drinking water or food supplements, could pose a potential risk to human health-particularly in certain subpopulations-when certain intake amounts, which are currently not well defined, are exceeded.

Analysis of aluminum, minerals and trace elements in the milk samples from lactating mothers in Hamadan, Iran

The present cross-sectional study is aimed at analyzing the breast milk of lactating mothers in Hamadan, Iran for aluminum and several minerals and trace elements. Ten governmental health care centers were utilized to facilitate collection of breast milk samples. The breast milk samples were collected at 1, 2, 6, 7, and 12 months postpartum from one hundred healthy lactating women, who delivered full-term newborns. Detection of sodium (Na), zinc (Zn), calcium (Ca), iron (Fe), copper (Cu), magnesium (Mg) and aluminum (Al) levels was conducted with the use of Inductively Coupled Plasma Mass Spectrometry (ICP-MS). This method has shown high accuracy, precision, sensitivity, and linearity for the wide range of concentrations. The accumulated data were not normally distributed; thus, the non-parametric Mann-Whitney U test was used in the statistical analysis of the results. Mean concentrations of Fe, Zn, Cu, Ca, Mg, and Na were 0.75, 1.38, 0.35, 255, 34.58, and 155.72 μg/mL, respectively. The mean level of Al, a well-known neurotoxic metal, was determined to be an alarming 0.191 μg/mL. Moreover, 95% of participants contained very harmful concentrations of Al in their milk. This study also revealed Zn deficiency in about 50% of milk samples. Further investigation is needed to elucidate sources of exposure and factors that may influence maternal and fetal exposure to aluminum.

Zinc Content in Breast Milk and Its Association with Maternal Diet

BACKGROUND

Zinc is an indispensable element, being involved in many biological processes. Correspondingly, insufficient zinc intake in early youth can detrimentally affect the function of a growing body. The aim of this study was to determine zinc content in breast milk among lactating women in Latvia and factors (maternal diet; mother's and baby's characteristics; breastfeeding pattern) affecting it.

METHODS

In total, 62 mature milk (at least one month postpartum) samples were collected and pooled within 24 h. Zinc content (mg 100 mL-1) was determined using inductively coupled plasma mass spectrometry (ICP-MS; Agilent 7700×, Agilent Technologies, Tokyo, Japan).

RESULTS

Zinc content in mature breast milk ranged from 0.01 to 0.34 mg 100 mL-1 with a median (interquartile range) content of 0.10 (0.05⁻0.15) mg 100 mL-1. Time postpartum was a significant negative predictor for zinc content in breast milk (r = -0.500; p = 0.000). Median maternal zinc intake was 10.70 (7.24⁻15.27) mg. Yet, zinc content in breast milk was unaffected by maternal dietary zinc intake (r = 0.155; p = 0.221).

CONCLUSIONS

Maternal dietary zinc intake was nearly the recommended intake for lactating women (11 mg), but due to low zinc content in breast milk, babies in Latvia might not receive sufficient zinc intake. Future research should aim for the assessment of zinc status by evaluating plasma or serum levels of both mothers and babies.

Analyses of Essential Elements and Heavy Metals by Using ICP-MS in Maternal Breast Milk from Şanlıurfa, Turkey

Maternal breast milk is a unique biological matrix that contains essential micronutrients. Potentially heavy metals may also affect infants' health and growth through maternal breast milk. The purpose of this study was to determine and compare the essential elements and heavy metals of maternal breast milk of nursery mothers residing in Şanlıurfa province, Turkey. Maternal breast milk concentrations of sodium, magnesium, phosphorus, potassium, calcium, iron, copper, zinc, arsenic, and lead were analyzed in a random sample of the first time in urban and suburban nursery Turkish mothers (n: 42). Eight essential elements and two heavy metals were analyzed using ICP-MS after microwave digestion. For bivariate analyses of variables, we use nonparametric Spearman's correlation coefficient test. The mean concentrations of essential elements and heavy metals were as follows: sodium 330 ± 417 mg/L, magnesium 32.6 ± 15.5 mg/L, phosphorus 156 ± 46.2 mg/L, potassium 488 ± 146 mg/L, calcium 193 ± 53.2 mg/L, iron 1.65 ± 1.43 mg/L, copper 0.54 ± 0.46 mg/L, zinc 2.89 ± 3.23 mg/L, arsenic < 1 μg/L, and lead < 1 μg/L. Concentrations of heavy metals in maternal breast milk may have the important implication that it is not affected by environmental pollution in this province. This study provides reliable information about maternal breast milk concentrations of nursery mothers residing in Şanlıurfa, Turkey, and also compares the relations between essential elements and socioeconomic conditions, residing areas, and using copper equipment for food preparation of which some have not previously been reported.

"Exosomics"-A Review of Biophysics, Biology and Biochemistry of Exosomes With a Focus on Human Breast Milk

Exosomes are biomolecular nanostructures released from cells. They carry specific biomolecular information and are mainly researched for their exquisite properties as a biomarker source and delivery system. We introduce exosomes in the context of other extracellular vesicles, describe their biophysical isolation and characterisation and discuss their biochemical profiling. Motivated by our interest in early-life nutrition and health, and corresponding studies enrolling lactating mothers and their infants, we zoom into exosomes derived from human breast milk. We argue that these should be more extensively studied at proteomic and micronutrient profiling level, because breast milk exosomes provide a more specific window into breast milk quality from an immunological (proteomics) and nutritional (micronutrient) perspective. Such enhanced breast milk exosome profiling would thereby complement and enrich the more classical whole breast milk analysis and is expected to deliver more functional insights than the rather descriptive analysis of human milk, or larger fractions thereof, such as milk fat globule membrane. We substantiate our arguments by a bioinformatic analysis of two published proteomic data sets of human breast milk exosomes.

Lactoferrin level in breast milk: a study of 248 samples from eight regions in China

Lactoferrin plays an important role in infant gastrointestinal health and immunity responses.

Vitamin D and calcium in the human breast milk

Vitamin D and calcium in the human milk is essential for the growth and the prevention of rickets in infants. In this review, we will discuss the physiology and the functions of vitamin D and calcium and the mechanisms of vitamin D and calcium transfer into the human breast milk. This review describes the recommended intake of vitamin D and calcium for infants and lactating mothers and the factors influencing the content of vitamin D and calcium in human milk. Furthermore, the measurement of vitamin D compounds and calcium in human breast milk is described in this review.

Concentrations of Carotenoids and Tocopherols in Breast Milk from Urban Chinese Mothers and Their Associations with Maternal Characteristics: A Cross-Sectional Study

Milk composition remains the best estimate of infant requirements. The aims of this study were to quantify carotenoids and tocopherols in human milk from healthy Chinese mothers, and to explore their associations with lactation stage, region, socio-economic and obstetric characteristics, and dietary intake. Human milk was obtained from 509 healthy mothers, and concentrations of carotenoids and tocopherols were analyzed by Ultra High Performance Liquid Chromatography. The mothers’ socio-economic and obstetric characteristics and dietary intake through a single 24-h dietary recall were evaluated. The median concentrations (μg/100 mL) of each component of 0–4 days, 5–11 days, 12–30 days, 31–60 days, 61–120 days, and 121–240 days postpartum were respectively as follows: β-carotene 8.0, 2.8, 2.1, 1.7, 1.9, 1.8; β-cryptoxanthin 6.2, 3.4, 2.4, 1.7, 1.8, 2.1; lutein 5.7, 7.0, 2.2, 2.9, 2.8, 3.7; lycopene 6.3, 2.5, 1.8, 1.4, 1.4, 1.5; zeaxanthin 1.0, 1.4, 0.8, 0.8, 1.0, 1.1; α-tocopherol 645, 382, 239, 206, 212, 211; γ-tocopherol 68, 63, 70, 73, 68, 88. The levels of those components varied significantly among different lactation stages and presented regional differences. Associations of carotenoid contents with maternal education, delivery mode, and present body mass index were found in multivariate analyses. These results suggested that lactation stage, region, and socio-economic and obstetric factors were associated with human milk concentrations of carotenoids and tocopherols in healthy Chinese mothers.

Human Milk and Allergic Diseases: An Unsolved Puzzle

There is conflicting evidence on the protective role of breastfeeding in relation to the development of allergic sensitisation and allergic disease. Studies vary in methodology and definition of outcomes, which lead to considerable heterogeneity. Human milk composition varies both within and between individuals, which may partially explain conflicting data. It is known that human milk composition is very complex and contains variable levels of immune active molecules, oligosaccharides, metabolites, vitamins and other nutrients and microbial content. Existing evidence suggests that modulation of human breast milk composition has potential for preventing allergic diseases in early life. In this review, we discuss associations between breastfeeding/human milk composition and allergy development.

Retinol, α-tocopherol, and selected minerals in breast milk of lactating women with full-term infants in South Korea

BACKGROUND/OBJECTIVES

This study was performed to measure fat-soluble vitamins and minerals in breast milk of Korean lactating mothers who exclusively breastfed their babies.

SUBJECTS/METHODS

Breast milk samples were collected from 334 mothers. Concentrations of retinol and α-tocopherol were analyzed by high performance liquid chromatography ultraviolet spectrometry while concentrations of minerals were measured by inductively coupled plasma optical emission spectrometry.

RESULTS

Retinol and α-tocopherol contents of breast milk were 39.58 ± 19.64 µg/dL and 0.23 ± 0.13 mg/dL, respectively. Average sodium, potassium, calcium, phosphorus, and magnesium levels in breast milk were 11.11 ± 5.16, 38.56 ± 9.01, 27.87 ± 6.10, 13.56 ± 3.30, and 3.05 ± 0.65 mg/dL, respectively. Contents of trace elements such as iron, zinc, copper, and manganese were 40.26 ± 46.21, 98.40 ± 62.47, 24.09 ± 9.03, and 0.90 ± 1.63 µg/dL, respectively. Fat-soluble vitamin concentration was positively correlated with total fat in milk samples, but no significant differences were observed in levels of retinol, α-tocopherol, or minerals based on whether or not lactating women were taking dietary supplements.

CONCLUSIONS

Micronutrient contents of breast milk samples from Korean lactating women were comparable to those of other nations. Retinol and α-tocopherol levels were correlated and also with total fat in breast milk.

Working group reports: evaluation of the evidence to support practice guidelines for nutritional care of preterm infants-the Pre-B Project

The "Evaluation of the Evidence to Support Practice Guidelines for the Nutritional Care of Preterm Infants: The Pre-B Project" is the first phase in a process to present the current state of knowledge and to support the development of evidence-informed guidance for the nutritional care of preterm and high-risk newborn infants. The future systematic reviews that will ultimately provide the underpinning for guideline development will be conducted by the Academy of Nutrition and Dietetics' Evidence Analysis Library (EAL). To accomplish the objectives of this first phase, the Pre-B Project organizers established 4 working groups (WGs) to address the following themes: 1) nutrient specifications for preterm infants, 2) clinical and practical issues in enteral feeding of preterm infants, 3) gastrointestinal and surgical issues, and 4) current standards of infant feeding. Each WG was asked to 1) develop a series of topics relevant to their respective themes, 2) identify questions for which there is sufficient evidence to support a systematic review process conducted by the EAL, and 3) develop a research agenda to address priority gaps in our understanding of the role of nutrition in health and development of preterm/neonatal intensive care unit infants. This article is a summary of the reports from the 4 Pre-B WGs.

Gene expression in breastmilk cells is associated with maternal and infant characteristics

Breastmilk is a rich source of cells with a heterogeneous composition comprising early-stage stem cells, progenitors and more differentiated cells. The gene expression profiles of these cells and their associations with characteristics of the breastfeeding mother and infant are poorly understood. This study investigated factors associated with the cellular dynamics of breastmilk and explored variations amongst women. Genes representing different breastmilk cell populations including mammary epithelial and myoepithelial cells, progenitors, and multi-lineage stem cells showed great variation in expression. Stem cell markers ESRRB and CK5, myoepithelial marker CK14, and lactocyte marker α-lactalbumin were amongst the genes most highly expressed across all samples tested. Genes exerting similar functions, such as either stem cell regulation or milk production, were found to be closely associated. Infant gestational age at delivery and changes in maternal bra cup size between pre-pregnancy and postpartum lactation were associated with expression of genes controlling stemness as well as milk synthesis. Additional correlations were found between genes and dyad characteristics, which may explain abnormalities related to low breastmilk supply or preterm birth. Our findings highlight the heterogeneity of breastmilk cell content and its changes associated with characteristics of the breastfeeding dyad that may reflect changing infant needs.

Importance of Exclusive Breastfeeding and Complementary Feeding among Infants

The aim of this review is to document the advantages of exclusive breastfeeding along with concerns which may hinder the practice of breastfeeding and focuses on the appropriateness of complementary feeding and feeding difficulties which infants encounter. Breastfeeding, as recommended by the World Health Organisation, is the most cost effective way for reducing childhood morbidity such as obesity, hypertension and gastroenteritis as well as mortality. There are several factors that either promote or act as barriers to good infant nutrition. Factors which influence breastfeeding practice in terms of initiation, exclusivity and duration are namely breast engorgement, sore nipples, milk insufficiency and availability of various infant formulas. On the other hand, introduction of complementary foods, also known as weaning, is done around 4 to 6 months and mothers usually should start with home-made nutritious food. Difficulties encountered during the weaning process are often refusal to eat followed by vomiting, colic, allergic reactions and diarrhoea.

A review on the genetic, environmental, and lifestyle aspects of the early-life origins of cardiovascular disease

This article is a comprehensive review on developmental origins of health and disease regarding various factors related to the origins of cardiovascular diseases from early life. It presents a summary of the impacts of various factors such as epigenetics; gene-environment interaction; ethnic predisposition to cardiovascular diseases and their underlying risk factors; prenatal factors; fetal programming; maternal weight status and weight gain during pregnancy; type of feeding during infancy; growth pattern during childhood; obesity; stunting; socioeconomic status; dietary and physical activity habits; active, secondhand, and thirdhand smoking, as well as environmental factors including air pollution and global climate change on the development and progress of cardiovascular diseases and their risk factors. The importance of early identification of predisposing factors for cardiovascular diseases for primordial and primary prevention of cardiovascular diseases from early life is highlighted.

Can we define an infant's need from the composition of human milk?

Human milk is recommended as the optimal nutrient source for infants and is associated with several short- and long-term benefits for child health. When accepting that human milk is the optimal nutrition for healthy term infants, it should be possible to calculate the nutritional needs of these infants from the intake of human milk. These data can then be used to design the optimal composition of infant formulas. In this review we show that the composition of human milk is rather variable and is dependent on factors such as beginning or end of feeding, duration of lactation, diet and body composition of the mother, maternal genes, and possibly infant factors such as sex. In particular, the composition of fatty acids in human milk is quite variable. It therefore seems questionable to estimate the nutritional needs of an infant exclusively from the intake of human milk. The optimal intake for infants must be based, at least in part, on other information-eg, balance or stable-isotope studies. The present recommendation that the composition of infant formulas should be based on the composition of human milk needs revision.

Effect of antibiotic treatment on intestinal microbial and enzymatic development in postnatally overfed obese rats

OBJECTIVE

To investigate the effect of the microbiota-induced changes and early overfeeding after amoxicillin administration (a) in suckling pups via their dams up to 15 days of lactation and (b) in weaned pups on intestinal microbial/functional adaptability and obesity development in male Sprague-Dawley rats.

DESIGN AND METHODS

Postnatal nutrition was elicited by adjusting the number of pups in the nest to 4 (small litters [SLs]) and 10 (normal litters [NLs]), while from days 21 to 40, both groups were fed with a standard diet. The numbers of Bacteroides/Prevotella (BAC) and Lactobacillus/Enterococcus (LAB) in the jejunum and colon were determined by fluorescence in situ hybridization technique, and jejunal alkaline phosphatase (AP), α-glucosidase and aminopeptidase activity was assayed histochemically.

RESULTS

On day 40, the SL in comparison with NL animals displayed excess weight/fat gain accompanied by higher LAB and lower numbers of BAC, and with permanently higher AP activity. Moreover, these acquired changes continued in SL vs. NL rats and were not influenced by antibiotic treatment, which induced significant decrease in the quantity of LAB and BAC.

CONCLUSIONS

These findings highlight the role of early life overfeeding upon the gut microbial/functional ontogeny and allow to distinguish their potential involvement in later risk of obesity.

Metals and trace element concentrations in breast milk of first time healthy mothers: a biological monitoring study

BACKGROUND

Breast milk is the best source of nutrition for the newborn infant. However, since all infants cannot be breast-fed, there is a need for background data for setting adequate daily intakes. Previously, concentration data on major essential elements and some toxic elements in breast milk, based on different analytical techniques, have been published. There is no recent study on a large number of metals and trace elements in breast milk, using a sensitive analytical method for determination of low element concentrations.

METHODS

Breast milk concentrations of 32 metals and elements in early lactation (days 14-21) were determined in a random sample of first time Swedish mothers (n = 60) using inductively coupled plasma mass spectrometry (ICPMS).

RESULTS

There were small inter-individual concentration variations in the macroelements Ca, K, Mg, P and S, and striking similarities across studies and over time, supporting a tight regulation of these elements in breast milk. Large inter-individual and over time differences were detected for Na concentrations, which may reflect an increase in salt consumption in Swedish women. Large inter-individual differences were also detected for the microelements Co, Cr, Mn and Mo, and the toxic metals As, Cd, Pb, Sb and V. Arsenic and B were positively correlated with fish consumption, indicating influence of maternal intake on breast milk concentrations. Observed differences in breast milk element concentrations across studies and over time could be attributed to the timing of sampling and a general decline over time of lactation (Cu, Fe, Mo, Zn), a possible lack of regulation of certain elements in breast milk (As, B, Co, Mn, Se) and time trends in environmental exposure (Pb), or in some cases to differences in analytical performance (Cr, Fe).

CONCLUSIONS

This study provides reliable updated information on a number of metals and elements in breast milk, of which some have not previously been reported.

Immune factors and fatty acid composition in human milk from river/lake, coastal and inland regions of China

Breast milk fatty acid composition may be affected by the maternal diet during gestation and lactation. The influence of dietary and breast milk fatty acids on breast milk immune factors is poorly defined. We determined the fatty acid composition and immune factor concentrations of breast milk from women residing in river/lake, coastal and inland regions of China, which differ in their consumption of lean fish and oily fish. Breast milk samples were collected on days 3–5 (colostrum), 14 and 28 post-partum (PP) and analysed for soluble CD14 (sCD14), transforming growth factor (TGF)-β1, TGF-β2, secretory IgA (sIgA) and fatty acids. The fatty acid composition of breast milk differed between the regions and with time PP. The concentrations of all four immune factors in breast milk decreased over time, with sCD14, sIgA and TGF-β1 being highest in the colostrum in the river and lake region. Breast milk DHA and arachidonic acid (AA) were positively associated, and γ-linolenic acid and EPA negatively associated, with the concentrations of each of the four immune factors. In conclusion, breast milk fatty acids and immune factors differ between the regions in China characterised by different patterns of fish consumption and change during the course of lactation. A higher breast milk DHA and AA concentration is associated with higher concentrations of immune factors in breast milk, suggesting a role for these fatty acids in promoting gastrointestinal and immune maturation of the infant.