Composition Of Human Milk Research Articles

The unrevealed links: periodontal health, human milk composition, and infant gut microbiome dynamics.

This review aims to identify the mechanistic relationships related to periodontal diseases and its possible association with changes in human milk composition and the composition and function of infants' gut microbiome. Maternal health conditions, especially inflammatory, are associated with altered human milk composition. It is not known whether maternal oral inflammatory diseases, including periodontal diseases, deleteriously affect human milk composition. A narrative review was conducted according to SANRA, the Scale for the Assessment of Narrative Review Articles, guidelines. PubMed, Google Scholar, and Cochrane database of systematic reviews were searched from September 2019 up to December 2023 using keywords such as breast/human milk, maternal health/infections, and periodontal diseases. Reference lists of relevant articles were also screened. Our primary outcome of interest was human milk composition (i.e., any changes in macronutrients, immunological components, etc.). Secondary outcomes included changes in human milk microbiome and subsequent changes in the infant gut microbiome. Outcomes were synthesized using a narrative approach where the existing evidence and current literature were summarized. No risk of bias assessment of the studies was performed in this review. The search yielded no studies investigating the relationship between periodontal diseases in nursing mothers and changes in human milk composition. However, a dose-response relationship exists between the severity of periodontal diseases and the risk of adverse pregnancy outcomes such as preterm birth. Mastitis and diabetes affected milk lipids. Immunoglobulin A (sIgA) was increased in mastitis, whereas reduced concentrations were reported in diabetes. Potential biological pathways through which periodontal diseases can negatively affect human milk composition include the systemic dissemination of inflammatory cytokines like IL-6, PGE2, and tumor necrosis factor (TNF)-β that can be up-regulated by bacterial by-products. This biological plausibility needs to be investigated, given the potentially negative impact on the quality of human milk that could be caused by periodontal inflammation.

Macronutrient concentrations in human milk beyond the first half year of lactation: a cohort study

ObjectiveHuman milk composition is dynamic. While extensive research has focused on its macronutrient concentrations during the first 6 months of lactation, limited research exists for extended lactation periods. This study...

Modelling the temporal trajectories of human milk components.

This paper demonstrates how available data can be explored and utilized to conclude generic patterns in the temporal changes in Human Milk (HM) composition. The temporal trajectories of selected human milk components (HMC-s) were described, in the first four months postpartum, by a primary model consisting of two phases: a short linear phase in the colostrum, triggered by the parturition; and a longer second phase, where the concentration of the component converges to a steady state. The model was fitted to data available in a recently published database of temporal HMC trajectories both at the levels of individual molecules (such as specific fatty acid, oligosaccharide, and mineral molecules) and molecule-groups (such as total protein, total fat). The properties of the trajectories suggest that experimental designs should follow non-equidistant sampling times, with increasingly longer time intervals after the first week postpartum. A selected parameter, the final stationary level, of the primary model was then studied as a function of geographical location (secondary modelling). We found that the total variation of the concentration of specific HMC-s is dominantly due to the inherent biological differences between individual mothers and to less extent to the geographical location.

Effect of hepatitis B virus infection on the nutrient composition of human breast milk: A prospective cohort study

Effect of hepatitis B virus infection on the nutrient composition of human breast milk: A prospective cohort study

Regional and longitudinal dynamics of human milk protein components assessed by proteome analysis on a fast and robust micro-flow LC–MS/MS system

An in-depth exploration of molecular composition of human milk could provide a scientific basis for the development of substitutes. The present study was conducted to analyze human milk proteins from 110 individuals from five regions of China and across three stages of lactation to investigate the change patterns. We developed a micro-flow liquid chromatography tandem mass spectrometry (μLC–MS/MS) system with data-independent acquisition (DIA) proteomics technology that can rapidly and stably characterize the human milk proteome. In total, 2796 proteins were identified. Among these proteins, CPM, ACSL1, and RPL13 changed significantly during lactation, and SCP2, GALK1 and GALE changed significantly between regions. Bioinformatics analysis revealed that human milk is altered by complex interactions between genetic and environmental factors. Our results not only reveal the regional and longitudinal patterns of change in human milk proteome but also provide theoretical basis and technical support for the production and quality control of infant formula.

Day-to-Day Fluctuation in Micronutrient Content in Human Milk Relative to Maternal Diet.

The impact of daily variations in habitual maternal intake on human milk (HM) composition has been poorly studied. We aimed to investigate the associations between day-to-day fluctuation in the micronutrient concentration in HM and daily maternal diet. To this end, an observational longitudinal study was carried out. A total of 143 lactating women each compiled a five-day weighed dietary record and concomitantly expressed milk for four successive days. Maternal daily intakes of micronutrients and food groups were analyzed. Free thiamine, free riboflavin, nicotinamide, pantothenic acid, pyridoxal, folic acid, cobalamin, ascorbic and dehydroascorbic acids, retinol, alpha- and gamma-tocopherol, cholecalciferol, and calcidiol in HM were determined for each of the four investigated days. A longitudinal data analysis with generalized estimating equation models was performed. For each daily serving of meat, fish, and eggs, total vitamin D3 levels increased by 243.2 pg/mL (p = 0.027) and selenium levels increased by 0.16 ppb (p = 0.031) in HM. For every 1 mg/day of riboflavin supplementation, free riboflavin levels in HM increased by 28.6 mcg/L (p = 0.019). Pyridoxal levels in HM increased by 6.3 mcg/L per 1 mg/day of vitamin B6 supplementation (p = 0.001), and by 2 mcg/L per daily fruit ration (p = 0.016). In conclusion, we were able to quantify the impact of the usual day-to-day variations in the diet and in the intake of commonly used supplements on the fluctuation of vitamin D, free riboflavin, pyridoxal, and selenium concentration in the milk of lactating women.

Maternal Nutrition and Human Milk Nutrients

Abstract Purpose: To explore the influence of maternal nutrition factors, including body mass index, nutritional supplementation, and dietary intake during the breastfeeding period, on macro and micronutrient composition in human milk. Study Design and Methods: We conducted a scoping review using the PRISMA-ScR checklist, initially identifying 5,984 original studies published in the English language from PubMed, Scopus, and Web of Science that presented findings on the association of maternal nutritional factors on human milk nutrient composition. After screening the title and abstract, we selected 69 studies for full review, including 3 studies found through checking reference lists. After full review, we included 23 studies in this scoping review. Results: Most studies found maternal body mass index and supplement consumption affected human milk macro and micronutrient composition, whereas inconsistent results were found on the relationship between maternal diet and human milk nutrients. Methodologies varied substantially across studies, especially for milk sample collection methods and maternal nutrition assessments. Clinical implications: Maternal nutrition factors may affect levels of human milk nutrients, requiring maternal nutrition monitoring during breastfeeding. However, given the considerable variability in the results between studies and methodological approaches, further studies should use standardized and validated procedures to strengthen the findings on this topic.

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

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). 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. 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. 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.

Maternal Mediterranean Diet During Lactation and Infant Growth.

Background: Human milk is considered the optimal source of nutrition for infants. Maternal diet is associated with the composition of human milk. The Mediterranean diet (MedDiet) has been studied in pregnancy and during lactation, and it has been associated with changes in milk composition, yet there is a lack of research on MedDiet during lactation and infant outcomes. Methods: Mother-infant dyads (n = 167) from ABC Baby, a prospective observational study, were included in this analysis. Maternal diet was obtained using an adapted version of the National Cancer Institute Diet History Questionnaire II, at 2 weeks or 2 months postpartum. Maternal MedDiet score was calculated using servings of vegetables, fruits, whole grains, nuts and seeds, legumes, fish, monounsaturated-to-saturated fatty acid ratio, red and processed meats, and added sugar. Infants' length, weight, and flank skinfold thickness were measured at 6 months. Using World Health Organization standards, weight-for-age (WAZ), length-for-age (LAZ), and weight-for-length (WLZ) Z-scores were calculated. Multiple linear regression models were adjusted for potential confounders. Results: Higher maternal MedDiet score and intake of fruit and fish were associated with lower flank skinfold thickness (β = -0.33, -0.52, and -1.26, respectively). Intake of nuts and seeds was associated with higher WLZ (β = 0.29). Intake of red and processed meats was associated with lower WAZ (β = -0.18) and LAZ (β = -0.18). Energy-adjusted added sugar intake was associated with lower WLZ (β = -0.02). Conclusions: The maternal MedDiet score was associated with lower skinfold thickness, while its components were associated with differences in anthropometric Z-scores. Further research on the maternal MedDiet and corresponding human milk composition is needed to explore this relationship.

Associations between SARS-CoV-2 Infection or COVID-19 Vaccination and Human Milk Composition: A Multi-Omics Approach

BackgroundThe risk of contracting SARS-CoV-2 via human milk-feeding is virtually non-existent. Adverse effects of COVID-19 vaccination for lactating individuals are not different from the general population, and no evidence has been found that their infants exhibit adverse effects. Yet, there remains substantial hesitation among this population globally regarding the safety of these vaccines. ObjectiveHerein we aimed to determine if compositional changes in milk occur following infection or vaccination, including any evidence of vaccine components. Methods and ResultsUsing a subset of milk samples obtained as part of our broad studies examining the effects on milk of SARS-CoV-2 infection and COVID-19 vaccination, an extensive multi-omics approach, we found that compared to unvaccinated individuals SARS-CoV-2 infection was associated with significant compositional differences in 67 proteins, 385 lipids, and 13 metabolites. In contrast, COVID-19 vaccination was not associated with any changes in lipids or metabolites, although it was associated with changes in 13 or fewer proteins. Compositional changes in milk differed by vaccine. Changes following vaccination were greatest after 1-6 hours for the mRNA-based Moderna vaccine (8 changed proteins), 3 days for the mRNA-based Pfizer (4 changed proteins), and adenovirus-based Johnson and Johnson (13 changed proteins) vaccines. Proteins that changed after both natural infection and Johnson and Johnson vaccine were associated mainly with systemic inflammatory responses. In addition, no vaccine components were detected in any milk sample. ConclusionsTogether, our data provide evidence of only minimal changes in milk composition due to COVID-19 vaccination, with much greater changes after natural SARS-CoV-2 infection.

Impact of cultural, nutrition, and lifestyle transition on human milk composition between the Orang Asli communities in Peninsular Malaysia: A study protocol.

Background: Human milk provided by healthy, well-nourished mothers represents the best food available for infants. Human milk is species-specific and recommended as the sole source of nutrition for the first 6 months of life and is an important food source until the infants reach 2 years of life. Unlike infant formula, which has a standardized composition, human milk composition varies among and within women. Aim: While many studies of human milk composition have been conducted, none have been done among the Orang Asli people in Malaysia. Hence, this study protocol is designed to determine the human milk composition of the Orang Asli in Peninsular Malaysia and how the transition of culture, nutrition, and different lifestyle experiences will affect the nutrient content of their milk. Methods: Quantitative (interviewer-administered questionnaire) and qualitative (focus group discussion) approaches will be employed in this study and in addition, laboratory works will also be carried out to analyze the nutrient composition of the milk samples collected from various Orang Asli subethnic groups in Peninsular Malaysia. Conclusion: Standardized, multipopulation studies of human milk composition are sorely needed to create a rigorous, comprehensive reference inclusive of nutrients and other factors. The establishment of any dietary parameters positively affecting the nutrient content of human milk may help design healthcare strategies in Malaysia to improve the quality of human milk and therefore the infants' health status.

Triacylglycerols in human milk and their association with edible oils in maternal diet: A study of five regions in China

Triacylglycerol (TAG) is the predominant lipid in human milk fat (∼98 %). The association between TAG and maternal diet is interesting but barely understood. In this study, we analyzed the TAG composition in human milk of mothers consuming seven edible oils during three lactation stages in five cities in China. UPLC-Q-TOF-MS was used to identify 147 species of TAGs. TAGs containing palmitic acid (P-TAG) and oleic acid (O-TAG) were significantly higher, whereas medium- and long-chain TAG was significantly lower (P < 0.05) in colostrum compared to transitional and mature milk. PLS-DA plots indicated the total TAG composition varied in different lactation stages and economic regions. Mothers consuming sunflower oil contained significantly lower (P < 0.05) P-TAG and O-TAG in their milk than the peanut oil group. O-P-L was significantly (P < 0.05) lower in rapeseed and olive oil groups. Significantly lower (P < 0.05) contents of TAGs containing linoleic acid (L-TAG) and polyunsaturated fatty acids (PUFA-TAG) were observed in the high oleic acid oil group. All the estimated factors explained 12.20 % – 33.40 % of the variation in different TAGs. These results contribute to a better nutrition strategy of maternal edible oils to promote breastfeeding.

Amino acid requirements of the infant: the amino acid composition of human breast milk.

The recommended amino acid requirements of the infant are based on the amino acid composition of mature human breast milk. The amino acid composition of breast milk is usually determined following either acid or alkaline (for tryptophan) hydrolysis. For accuracy, however, the known effect of hydrolysis time on amino acid composition should be accounted for. Also, ideally the amino acid composition of breast milk should be given in units of digested (assumed to be absorbed) amino acids. A review of the literature is presented which gives mean total amino acid concentrations in mature human milk (n = 26 studies), mean hydrolysis correction factors (n = 3 studies) and mean true ileal amino acid digestibility coefficients (n = 3 studies, suckling piglet). There were differences between the estimates of amino acid concentration corrected for hydrolysis time and digestibility, and current FAO (2013) recommendations that were not corrected for these factors. The values based on the published literature up until 2023 (mg/g true protein) corrected for hydrolysis time and digestibility gave higher values (more than 16% higher) for leucine, lysine and threonine, and considerably higher values (greater than 30%) for histidine and tryptophan. Current recommendations may need revision.

Maternal dietary protein and amino acid intake is not associated with the amino acid composition of human milk in an affluent environment.

Amino acids (AA) are essential nutrients in human milk (HM) and critical for infant growth and development. Several maternal lifestyle factors have been suggested to influence HM AA composition, with possible consequences for the breastfed infant. Whether maternal dietary protein and AA intake is associated with AA concentrations in HM is still largely unknown. Therefore, the aim of this study was to investigate the association between maternal dietary AA intake and AA concentrations in HM over the first month postpartum. Data from the observational longitudinal Amsterdam Mother's Milk study were used, consisting of 123 lactating women in their first postpartum month. HM samples were collected three times, on day 10, 17 and 24 postpartum. Maternal dietary protein and AA intake on these collection days was assessed using three 24-h recalls. HM protein-bound and free AA (BAA and FAA, respectively) were analysed by liquid chromatography. Associations between maternal AA intake and AA concentrations in HM were assessed using linear mixed models. Maternal intake was negatively associated with milk concentrations of free arginine (-0·0003; P = 0·01) and free lysine (-0·0004; P = 0·03) and was positively associated with free glutamine (0·002; P = 0·03) and free threonine (0·0008; P = 0·03). However, these associations were attenuated after correction for multiple testing. Both the quality and quantity of dietary protein intake in lactating women do not seem to influence the amino composition of their breast milk when living in an affluent environment.

Comprehensive lipidomic profiling of human milk from lactating women across varying lactation stages and gestational ages

An untargeted lipidomic analysis was conducted to investigate the lipid composition of human milk across different lactation stages and gestational ages systematically. A total of 25 lipid subclasses and 934 lipid species as well as 90 free fatty acids were identified. Dynamic changes of the lipids throughout lactation and gestational phases were highlighted. In general, lactation stages introduced more variations in the lipid composition of human milk than gestational ages. Most lipids decreased as the milk progressed from the colostral stage to the mature stage, with some reaching a peak at the transitional stage. Significant variations in lipid composition across gestational ages were predominantly evident during early lactation period. In mature milks, most of the lipids exhibited no discernible statistical differences among gestational ages. This elucidation offers valuable insights and guidance for tailoring precise nutritional strategies for infants with diverse health needs.

Longitudinal investigation of mineral composition in human milk and its correlation with infant anthropometric outcomes among Tibetan mother-infant dyads during the first 6 months postpartum

Nutrients in human milk, including minerals, relate growth and development of breast-fed infants. Tibetan mother-infant dyads possess unique characteristics on early nutrition due to their featured long-lasting life-style. This study longitudinally investigated the relationship between the mineral composition in human milk and the Z-scores of infants among Tibetan mother-infant dyads during their first 6 months postpartum through a prospective cohort study. The results show that the minerals of Na, Mg, K, Ca, Cu, Zn, and Se were of higher levels in colostrum than other lactation stages. Several minerals were below the recommended values for infants according to Chinese dietary guidelines. Besides, a large proportion of infant Z-scores were below −2 as lactation period continued. Multivariate statistical analysis revealed that classifications and correlations in varying degrees were observed between minerals in human milk and infant Z-scores. These findings will be advantageous for research upon Chinese early nutrition and progress of tailor-made infant formula.

Investigation of Human Milk as a Biological System in a Multicenter Mother-Infant Cohort: Protocol Design and Cohort Profile of the Phoenix Study.

Breastfeeding and human milk are the gold standard for infant feeding. Studying human milk with a systems biology approach in a large longitudinal cohort is needed to understand its complexity and health implications. The Phoenix study is a multicenter cohort study focusing on the interactions of maternal characteristics, human milk composition, infant feeding practices, and health outcomes of Chinese mothers and infants. A total of 779 mother-infant dyads were recruited from November 2021 to September 2022, and 769 mother-infant dyads were enrolled in the study. Scheduled home visits took place at 1, 4, 6, and 12 months postpartum, and 696 dyads (90.5% participants) completed the 12-month visit. At each visit, maternal and infant anthropometry was assessed. Questionnaires were administered to collect longitudinal information on maternal characteristics and lifestyle, infant feeding, and health. Digital diaries were used to record maternal dietary intake, infant feeding, and stool character. Human milk, maternal feces, infant feces, and infant saliva were collected. An external pharmaceutical-level quality assurance approach was implied to ensure the trial quality. Multi-omics techniques (including glycomics, lipidomics, proteomics, and microbiomics) and machine learning algorithms were integrated into the sample and data analysis. The protocol design of the Phoenix study provides a framework for prospective cohort studies of mother-infant dyads and will provide insights into the complex dynamics of human milk and its interplay with maternal and infant health outcomes in the Chinese population.

A newborn's perspective on immune responses to food.

In this review, we will highlight infants' immune responses to food, emphasizing the unique aspects of early-life immunity and the critical role of breast milk as a food dedicated to infants. Infants are susceptible to inflammatory responses rather than immune tolerance at the mucosal and skin barriers, necessitating strategies to promote oral tolerance that consider this susceptibility. Breast milk provides nutrients for growth and cell metabolism, including immune cells. The content of breast milk, influenced by maternal genetics and environmental exposures, prepares the infant's immune system for the outside world, including solid foods. To do this, breast milk promotes immune system development through antigen-specific and non-antigen-specific immune education by exposing the newborn to food and respiratory allergens and acting on three key targets for food allergy prevention: the gut microbiota, epithelial cells, and immune cells. Building knowledge of how the maternal exposome and human milk composition influence offspring's healthy immune development will lead to recommendations that meet the specific needs of the developing immune system and increase the chances of promoting an appropriate immune response to food in the long term.

Investigation of Relationships between Intakes of Human Milk Total Lipids and Metabolic Hormones and Infant Sex and Body Composition.

Human milk (HM) composition, including metabolic hormones and lipids, is influenced by various factors, including lactation stage and, potentially, infant sex, which may affect infant body composition (BC) development. We aimed to: (a) characterize the longitudinal concentration and intake profiles of HM leptin, adiponectin, insulin, and total lipids; (b) determine if their concentrations and intakes differ by infant sex; and (c) explore the intakes relationships with the development of infant BC. Milk samples (n = 501) were collected from 82 mother-infant dyads during the first 6 months postpartum. Infant 24 h HM intake was measured, and the average cumulative HM component intakes were calculated. The statistical analysis used linear mixed modeling. Intakes of HM leptin, adiponectin, insulin, and total lipids increased to 1 month postpartum and then remained stable. HM intake and total lipids intake but not hormone intakes were positively associated with infant BC (fat-free mass, fat-free mass index, fat mass, fat mass index, percentage fat mass, and fat mass to fat-free mass ratio). HM component concentrations and intakes did not differ by sex. These findings advance our understanding of the temporal nature of HM components, emphasizing the role of infant 24 h HM and total lipids intake in development of infant lean and adipose tissue.

Poly- and Perfluoroalkyl Substances are Associated with the Composition of Human Milk

Poly- and Perfluoroalkyl Substances are Associated with the Composition of Human Milk