Maternal obesity and the human milk metabolome: associations with infant body composition and postnatal weight gain

Human Milk Composition Is Associated with Maternal Body Mass Index in a Cross-Sectional, Untargeted Metabolomics Analysis of Human Milk from Guatemalan Mothers

Background

Maternal overweight and obesity has been associated with poor lactation performance including delayed lactogenesis and reduced duration. However, the effect on human milk composition is less well understood.

Objectives

We evaluated the relationship of maternal BMI on the human milk metabolome among Guatemalan mothers.

Methods

We used data from 75 Guatemalan mothers who participated in the Household Air Pollution Intervention Network trial. Maternal BMI was measured between 9 and <20 weeks of gestation. Milk samples were collected at a single time point using aseptic collection from one breast at 6 mo postpartum and analyzed using high-resolution mass spectrometry. A cross-sectional untargeted high-resolution metabolomics analysis was performed by coupling hydrophilic interaction liquid chromatography (HILIC) and reverse phase C18 chromatography with mass spectrometry. Metabolic features associated with maternal BMI were determined by a metabolome-wide association study (MWAS), adjusting for baseline maternal age, education, and dietary diversity, and perturbations in metabolic pathways were identified by pathway enrichment analysis.

Results

The mean age of participants at baseline was 23.62 ± 3.81 y, and mean BMI was 24.27 ± 4.22 kg/m2. Of the total metabolic features detected by HILIC column (19,199 features) and by C18 column (11,594 features), BMI was associated with 1026 HILIC and 500 C18 features. Enriched pathways represented amino acid metabolism, galactose metabolism, and xenobiotic metabolic metabolism. However, no significant features were identified after adjusting for multiple comparisons using the Benjamini-Hochberg false discovery rate procedure (FDRBH < 0.2).

Conclusions

Findings from this untargeted MWAS indicate that maternal BMI is associated with metabolic perturbations of galactose metabolism, xenobiotic metabolism, and xenobiotic metabolism by cytochrome p450 and biosynthesis of amino acid pathways. Significant metabolic pathway alterations detected in human milk were associated with energy metabolism-related pathways including carbohydrate and amino acid metabolism.This trial was registered at clinicaltrials.gov as NCT02944682.

Understanding risk and causal mechanisms for developing obesity in infants and young children: A National Institutes of Health workshop

Obesity in children remains a major public health problem, with the current prevalence in youth ages 2-19 years estimated to be 19.7%. Despite progress in identifying risk factors, current models do not accurately predict development of obesity in early childhood. There is also substantial individual variability in response to a given intervention that is not well understood. On April 29-30, 2021, the National Institutes of Health convened a virtual workshop on "Understanding Risk and Causal Mechanisms for Developing Obesity in Infants and Young Children." The workshop brought together scientists from diverse disciplines to discuss (1) what is known regarding epidemiology and underlying biological and behavioral mechanisms for rapid weight gain and development of obesity and (2) what new approaches can improve risk prediction and gain novel insights into causes of obesity in early life. Participants identified gaps and opportunities for future research to advance understanding of risk and underlying mechanisms for development of obesity in early life. It was emphasized that future studies will require multi-disciplinary efforts across basic, behavioral, and clinical sciences. An exposome framework is needed to elucidate how behavioral, biological, and environmental risk factors interact. Use of novel statistical methods may provide greater insights into causal mechanisms.

Maternal exercise preserves offspring cardiovascular health via oxidative regulation of the ryanodine receptor

OBJECTIVE

The intrauterine environment during pregnancy is a critical factor in the development of obesity, diabetes, and cardiovascular disease in offspring. Maternal exercise prevents the detrimental effects of a maternal high fat diet on the metabolic health in adult offspring, but the effects of maternal exercise on offspring cardiovascular health have not been thoroughly investigated.

METHODS

To determine the effects of maternal exercise on offspring cardiovascular health, female mice were fed a chow (C; 21% kcal from fat) or high-fat (H; 60% kcal from fat) diet and further subdivided into sedentary (CS, HS) or wheel exercised (CW, HW) prior to pregnancy and throughout gestation. Offspring were maintained in a sedentary state and chow-fed throughout 52 weeks of age and subjected to serial echocardiography and cardiomyocyte isolation for functional and mechanistic studies.

RESULTS

High-fat fed sedentary dams (HS) produced female offspring with reduced ejection fraction (EF) compared to offspring from chow-fed dams (CS), but EF was preserved in offspring from high-fat fed exercised dams (HW) throughout 52 weeks of age. Cardiomyocytes from HW female offspring had increased kinetics, calcium cycling, and respiration compared to CS and HS offspring. HS offspring had increased oxidation of the RyR2 in cardiomyocytes coupled with increased baseline sarcomere length, resulting in RyR2 overactivity, which was negated in female HW offspring.

CONCLUSIONS

These data suggest a role for maternal exercise to protect against the detrimental effects of a maternal high-fat diet on female offspring cardiac health. Maternal exercise improved female offspring cardiomyocyte contraction, calcium cycling, respiration, RyR2 oxidation, and RyR2 activity. These data present an important, translatable role for maternal exercise to preserve cardiac health of female offspring and provide insight on mechanisms to prevent the transmission of cardiovascular diseases to subsequent generations.

Composition of Microbiota in Transient and Mature Human Milk: Significant Changes in Large for Gestational Age Group

The composition of the human milk (HM) microbiota and, consequently, the microorganisms that are passed on to the infant through breastfeeding, can be influenced by various factors such as the mother's health and diet, gestational age, delivery mode, lactation stage, method of infant feeding, and geographical location. The aim of the Human Milk-Gest Study was to compare the microbiota of transient (postpartum 7-15 days) and mature HM (postpartum 45-90 days) of 44 mothers, and to investigate any potential changes associated with preterm birth, mode of delivery, and birth weight in relation to gestational age. The data were classified into five study groups: normal spontaneous delivery-term (NS-T) newborns, cesarean delivery-term (CS-T) newborns, preterm (PT) newborns (with a gestational age of less than 37 weeks), small for gestational age (SGA) newborns, and large for gestational age (LGA) newborns. An analysis of differential abundance was conducted using ANCOM-BC to compare the microbial genera between transient and mature HM samples as well as between other study groups. A significant difference was detected between HM samples at different sampling times and between the study groups (p < 0.01). In transient HM samples, Ralstonia, Burkholderiaceae_uc, and Pelomonas were significantly dominant in the LGA group compared to the NS-T, CS-T, PT, and SGA groups. In mature HM samples, Burkholderiaceae_uc, Ralstonia, Pelomonas, and Klebsiella were significantly dominant in the LGA group compared to the NS-T, CS-T, and PT groups, while Ralstonia, Burkholderiaceae_uc, and Pelomonas were significantly dominant in the LGA group compared to the SGA group. Differences were also detected between the transient and mature HM samples in the CS-T, PT, SGA, and LGA groups, but no differences occurred in the NS-T groups. In conclusion, we showed that Ralstonia, Burkholderiaceae_uc, and Pelomonas were significantly dominant in the LGA group in transient HM and continued in mature HM. The body mass index (BMI) of the mothers in the LGA group was not >30 at conception, however, the maternal BMI at birth and maternal weight gain during pregnancy were higher than in the other groups. The nutritional composition of HM is specifically designed to meet infant nutritional requirements during early life. Evaluating the effects of HM microbiota on infant microbiota composition and short- and long-term health effects in larger studies would be useful.

Critical Factors in Sample Collection and Preparation for Clinical Metabolomics of Underexplored Biological Specimens

This review article compiles critical pre-analytical factors for sample collection and extraction of eight uncommon or underexplored biological specimens (human breast milk, ocular fluids, sebum, seminal plasma, sweat, hair, saliva, and cerebrospinal fluid) under the perspective of clinical metabolomics. These samples are interesting for metabolomics studies as they reflect the status of living organisms and can be applied for diagnostic purposes and biomarker discovery. Pre-collection and collection procedures are critical, requiring protocols to be standardized to avoid contamination and bias. Such procedures must consider cleaning the collection area, sample stimulation, diet, and food and drug intake, among other factors that impact the lack of homogeneity of the sample group. Precipitation of proteins and removal of salts and cell debris are the most used sample preparation procedures. This review intends to provide a global view of the practical aspects that most impact results, serving as a starting point for the designing of metabolomic experiments.

Prenatal Human Milk Oligosaccharides (HMOs) in the Context of BMI, Gestational Weight Gain, and Lipid Profile-An Association Study in Pregnant Women with Overweight or Obesity

BACKGROUND

Human milk oligosaccharides (HMOs) are bioactive glycans first detected in human milk. Their presence in maternal blood during pregnancy suggests systemic functions. Dynamics and associations of the most abundant prenatal HMOs in relation to maternal BMI and serum lipids in a cohort of 87 pregnant women with either overweight or obesity are studied.

METHODS

Serum HMOs (2'FL, 3'SL, 3'SLN, LDFT), serum lipids (total cholesterol, HDL, LDL, triglycerides), and BMI are measured at 15, 24, and 32 weeks of gestation.

RESULTS

2'FL and LDFT are negatively correlated to pre-pregnancy BMI and increase significantly slower between 15 and 24 weeks in highly obese women. Women without detectable increase of serum 2'FL (non-secretors) show a less pronounced gestational weight gain and lower BMI in the third trimester as compared to women phenotype as secretors. Higher early-pregnancy 2'FL is associated with high HDL and low triglycerides in pregnancy. On the other hand, higher 3'SL at 15 weeks is associated with higher triglycerides, LDL, and total cholesterol.

CONCLUSIONS

Higher early-pregnancy 2'FL is associated with a cardioprotective lipid profile, whereas higher 3'SL is associated with an atherogenic lipid profile. Serum trajectories of 2'FL and LDFT in obese women suggest an obesity mediated delay of α-1,2-fucosylation.

Exercised breastmilk: a kick-start to prevent childhood obesity?

Exercise has systemic health benefits through effects on multiple tissues, with intertissue communication. Recent studies indicate that exercise may improve breastmilk composition and thereby reduce the intergenerational transmission of obesity. Even if breastmilk is considered optimal infant nutrition, there is evidence for variations in its composition between mothers who are normal weight, those with obesity, and those who are physically active. Nutrition early in life is important for later-life susceptibility to obesity and other metabolic diseases, and maternal exercise may provide protection against the development of metabolic disease. Here we summarize recent research on the influence of maternal obesity on breastmilk composition and discuss the potential role of exercise-induced adaptations to breastmilk as a kick-start to prevent childhood obesity.

Human Milk Macronutrients and Child Growth and Body Composition in the First Two Years: A Systematic Review

Among exclusively breastfed infants, human milk (HM) provides complete nutrition in the first mo of life and remains an important energy source as long as breastfeeding continues. Consisting of digestible carbohydrates, proteins, and amino acids, as well as fats and fatty acids, macronutrients in human milk have been well studied; however, many aspects related to their relationship to growth in early life are still not well understood. We systematically searched Medline, EMBASE, the Cochrane Library, Scopus, and Web of Science to synthesize evidence published between 1980 and 2022 on HM components and anthropometry through 2 y of age among term-born healthy infants. From 9992 abstracts screened, 57 articles reporting observations from 5979 dyads were included and categorized based on their reporting of HM macronutrients and infant growth. There was substantial heterogeneity in anthropometric outcome measurement, milk collection timelines, and HM sampling strategies; thus, meta-analysis was not possible. In general, digestible carbohydrates were positively associated with infant weight outcomes. Protein was positively associated with infant length, but no associations were reported for infant weight. Finally, HM fat was not consistently associated with any infant growth metrics, though various associations were reported in single studies. Fatty acid intakes were generally positively associated with head circumference, except for docosahexaenoic acid. Our synthesis of the literature was limited by differences in milk collection strategies, heterogeneity in anthropometric outcomes and analytical methodologies, and by insufficient reporting of results. Moving forward, HM researchers should accurately record and account for breastfeeding exclusivity, use consistent sampling protocols that account for the temporal variation in HM macronutrients, and use reliable, sensitive, and accurate techniques for HM macronutrient analysis.

Human Milk Bioactive Components and Child Growth and Body Composition in the First 2 Years: A Systematic Review

Human milk (HM) contains macronutrients, micronutrients, and a multitude of other bioactive factors, which can have a long-term impact on infant growth and development. We systematically searched MEDLINE, EMBASE, Cochrane Library, Scopus, and Web of Science to synthesize evidence published between 1980 and 2022 on HM components and anthropometry through 2 y of age among term-born infants. From 9992 abstracts screened, 141 articles were included and categorized based on their reporting of HM micronutrients, macronutrients, or bioactive components. Bioactives including hormones, HM oligosaccharides (HMOs), and immunomodulatory components are reported here, based on 75 articles from 69 unique studies reporting observations from 9980 dyads. Research designs, milk collection strategies, sampling times, geographic and socioeconomic settings, reporting practices, and outcomes varied considerably. Meta-analyses were not possible because data collection times and reporting were inconsistent among the studies included. Few measured infant HM intake, adjusted for confounders, precisely captured breastfeeding exclusivity, or adequately described HM collection protocols. Only 5 studies (6%) had high overall quality scores. Hormones were the most extensively examined bioactive with 46 articles (n = 6773 dyads), compared with 13 (n = 2640 dyads) for HMOs and 12 (n = 1422 dyads) for immunomodulatory components. Two studies conducted untargeted metabolomics. Leptin and adiponectin demonstrated inverse associations with infant growth, although several studies found no associations. No consistent associations were found between individual HMOs and infant growth outcomes. Among immunomodulatory components in HM, IL-6 demonstrated inverse relationships with infant growth. Current research on HM bioactives is largely inconclusive and is insufficient to address the complex composition of HM. Future research should ideally capture HM intake, use biologically relevant anthropometrics, and integrate components across categories, embracing a systems biology approach to better understand how HM components work independently and synergistically to influence infant growth.

High-intensity exercise increases breast milk adiponectin concentrations: a randomised cross-over study

Introduction

Adiponectin plays a role in glucose and fat metabolism and is present in human breast milk. It has been postulated that higher breast milk adiponectin concentrations may prevent rapid weight gain in infancy. Prior research indicates that circulating adiponectin increases acutely after endurance exercise, but no prior research has investigated the effect of exercise on breast milk adiponectin concentrations. The purpose of this randomised, cross-over study was to determine the acute effects of endurance exercise on adiponectin concentrations in human breast milk.

Methods

Participants who were exclusively breastfeeding a 6-12 week-old term infant (N = 20) completed three conditions in the laboratory: (1) Moderate-intensity continuous training (MICT), (2) High-intensity interval training (HIIT), and (3) No activity (REST). At each condition, we collected breast milk at 07:00 h (before exercise/rest), 11:00 h (immediately after exercise/rest), 12:00 h (1 h after exercise/rest), and 15:00 h (4 h after exercise/rest) and determined adiponectin concentrations using enzyme-linked immunosorbent assay. We compared changes in adiponectin concentrations after MICT and HIIT, adjusted for the morning concentration on each test day, with those after REST, using paired t-tests.

Results

Adiponectin concentrations increased 1 h after HIIT, from 4.6 (± 2.2) μg/L in the 07:00 h sample to 5.6 (± 2.6) μg/L. This change was 0.9 μg/L (95% confidence interval 0.3 to 1.5) greater than the change between these two timepoints in the REST condition (p = 0.025). There were no other statistically significant changes in adiponectin concentrations.

Conclusion

HIIT may increase adiponectin concentrations in breast milk acutely after exercise. Further studies should determine the impact of exercise-induced elevations in breast milk adiponectin concentrations on growth and metabolism in infancy.

Understanding the Immunological Quality of Breast Milk in Maternal Overweight and Obesity

Maternal obesity, affecting many pregnant women globally, not only poses immediate health risks but also modulates breast milk composition. Obesity is linked to inflammation and oxidative stress, impacting breast milk's immune properties. This paper explores the intricate relationship between maternal metabolic disorders, such as obesity, and breast milk's immunological components. We conducted a thorough search for original and review articles published until 17 October 2023 in the PUBMED/Scopus database. This search included several terms related to human breast milk, immunological properties, and obesity. Articles were selected with the consensus of all authors. Maternal metabolic disorders have discernible effects on the composition of immune-related components in breast milk, such as immunoglobulins, lactoferrin, leptin, ghrelin, adiponectin, C-reactive protein, growth factors, extracellular vesicles, and lymphocytes. These changes in breast milk composition can significantly impact the newborn's immune system, with potential long-term health implications beyond the immediate postnatal period. Maternal metabolic health is a critical factor in shaping the health trajectory of the neonate through breastfeeding, although the full advantages of breastfeeding for children of mothers with obesity remain uncertain. Ongoing research aims to understand and unravel these links.

Randomised controlled trial of exercise training during lactation on breast milk composition in breastfeeding people with overweight/obesity: a study protocol for the MILKSHAKE trial

Breast milk from people with overweight/obesity may differ in composition compared with that from normal-weight people. Exercise training can modify breast milk composition in rodent models, with a beneficial impact demonstrated on the offspring's metabolism, but whether these findings translate to humans is unclear. This trial aims to determine the effect of an exercise intervention on breast milk composition and whether an exercise-induced modification of breast milk impacts the infants' growth and body composition. Effect of Exercise Training on Breastmilk Composition is a randomised, controlled trial with two parallel groups, one exercise group and one control group, with a 1:1 allocation. We will include a minimum of 62 exclusively breastfeeding participants, 6 weeks postpartum. The exercise intervention lasts 8 weeks and comprises 25 supervised endurance exercise sessions with moderate or high intensity. The primary outcome measure is the change in the relative concentration of the human milk oligosaccharide 3'sialyllactose in breast milk from baseline at 6 weeks postpartum to the end of the intervention period. Secondary outcomes include breast milk concentrations of other metabolites, cytokines, hormones and microRNA, maternal health outcomes, infant growth, infant gut microbiome and infant circulating microRNA. Maternal and infant outcomes will be measured before, during and after the intervention period, with a follow-up of the infants until they are 24 months old. Trial registration number NCT05488964.

Untargeted Metabolomic Analysis of Lactation-Stage-Matched Human and Bovine Milk Samples at 2 Weeks Postnatal

Epidemiological data demonstrate that bovine whole milk is often substituted for human milk during the first 12 months of life and may be associated with adverse infant outcomes. The objective of this study is to interrogate the human and bovine milk metabolome at 2 weeks of life to identify unique metabolites that may impact infant health outcomes. Human milk (n = 10) was collected at 2 weeks postpartum from normal-weight mothers (pre-pregnant BMI < 25 kg/m2) that vaginally delivered term infants and were exclusively breastfeeding their infant for at least 2 months. Similarly, bovine milk (n = 10) was collected 2 weeks postpartum from normal-weight primiparous Holstein dairy cows. Untargeted data were acquired on all milk samples using high-resolution liquid chromatography-high-resolution tandem mass spectrometry (HR LC-MS/MS). MS data pre-processing from feature calling to metabolite annotation was performed using MS-DIAL and MS-FLO. Our results revealed that more than 80% of the milk metabolome is shared between human and bovine milk samples during early lactation. Unbiased analysis of identified metabolites revealed that nearly 80% of milk metabolites may contribute to microbial metabolism and microbe-host interactions. Collectively, these results highlight untargeted metabolomics as a potential strategy to identify unique and shared metabolites in bovine and human milk that may relate to and impact infant health outcomes.

Human Cytomegalovirus in breast milk is associated with milk composition, the infant gut microbiome, and infant growth

Human cytomegalovirus (CMV) is a highly prevalent herpesvirus that is often transmitted to the neonate via breast milk. Postnatal CMV transmission can have negative health consequences for preterm and immunocompromised infants, but any effects on healthy term infants are thought to be benign. Furthermore, the impact of CMV on the composition of the hundreds of bioactive factors in human milk has not been tested. Here, we utilize a cohort of exclusively breastfeeding full term mother-infant pairs to test for differences in the milk transcriptome and metabolome associated with CMV, and the impact of CMV in breast milk on the infant gut microbiome and infant growth. We find upregulation of the indoleamine 2,3- dioxygenase (IDO) tryptophan-to-kynurenine metabolic pathway in CMV+ milk samples, and that CMV+ milk is associated with decreased Bifidobacterium in the infant gut. Our data indicate a complex relationship between milk CMV, milk kynurenine, and infant growth; with kynurenine positively correlated, and CMV viral load negatively correlated, with infant weight-for-length at 1 month of age. These results suggest CMV transmission, CMV-related changes in milk composition, or both may be modulators of full term infant development.

Maternal Diet May Modulate Breast Milk Microbiota-A Case Study in a Group of Colombian Women

There is increasing evidence that the diet and nutritional status of women during pregnancy and lactation can modulate the microbiota of their milk and, therefore, the microbiota of the infant. An observational, descriptive, and cross-sectional study was carried out in a group of lactating women. Dietary intake during gestation and the first trimester of lactation was evaluated, and the microbiota was analyzed by 16S ribosomal RNA (rRNA) sequencing using the Illumina platform. Globally, Streptococcus spp. (32%), Staphylococcus spp. (17.3%), Corynebacterium spp. (5.1%) and Veillonella spp. (3.1%) were the predominant bacterial genera. The consumption of simple carbohydrates in gestation (rho = 0.55, p ≤ 0.01) and lactation (rho = 0.50, p ≤ 0.01) were positively correlated with Enterobacter spp. In lactation, a negative correlation was observed between the intake of simple carbohydrates and the genus Bifidobacterium spp. (rho = -0.51 p ≤ 0.01); furthermore, a positive correlation was identified between the intake of folic acid and Akkermansia spp. (rho = 0.47, p ≤ 0.01). Amplicon sequence variants (ASVs) associated with the delivery mode, employment relationship, the baby's gender, birth weight, the Body Mass Index (BMI) of the breastfeeding woman, and gestational weight gain were recovered as covariates in a linear mixed model. The results of this research showed that the maternal nutritional status and diet of women during gestation and lactation could modulate the microbiota of breast milk.

Breastfeeding Duration and Timing of Bottle Supplementation: Associations with Body Mass Index from Childhood to Young-Adulthood

Evidence for the association between breastfeeding (BF) duration and later body mass index (BMI) is inconsistent. We explored how BF duration and BF type (exclusive or partial) related to BMI from childhood to young adulthood in a Chilean cohort. Infants were recruited at 6 months between 1994 and 1996 in Santiago, Chile (n = 821). Mothers reported date of first bottle and last BF; anthropometry was measured at 1, 5, 10, 16, and 23 years. We tested whether: (1) type of BF at 6 months (none, partial, exclusive) and (2) duration of exclusive BF (<1 month, 1 to <3 months, 3 to <6 months, and ≥6 months) related to BMI. At 6 months, 35% received both breastmilk and formula ("partial BF") and 38% were exclusively breastfed. We found some evidence of an association between longer BF and lower BMI z-scores at young ages but observed null effects for later BMI. Specifically, BF for 3 to <6 months compared to <1 month related to lower BMI z-scores at 1 and 5 years (both p < 0.05). Our results are in partial accordance with others who have not found a protective effect of longer BF for lower BMI.

Maternal Nutritional Status and the Microbiome across the Pregnancy and the Post-Partum Period

Appropriate nutrition during pregnancy and the post-partum period is vital for both the mothers and their offspring. Both under- and over-nourished status may have important microbial implications on the maternal and infant gut microbiomes. Alterations in the microbiome can have implications for a person's risk of obesity and metabolic diseases. In this review, we examine alterations in the maternal gut, vaginal, placental, and milk microbiomes in the context of pre-pregnancy BMI, gestational weight gain, body composition, gestational diabetes, and maternal diet. We also investigate how the infant gut microbiome may be altered by these different parameters. Many of the microbial changes seen in under- and over-nourished states in birthing parents may result in long-term implications for the health of offspring. Differences in diet appear to be a major driver of the maternal and subsequently milk and offspring microbiomes. Further prospective longitudinal cohort studies are needed to examine nutrition and the microbiome to better understand its implications. Additionally, trials involving dietary interventions in child-bearing age adults should be explored to improve the mother and child's risks for metabolic diseases.

Body Condition and Fertility in Dogs

Ideal body condition and nutritional status in dogs is essential for quality of life, including reproductive health. Herein, we review the implications body condition, particularly fat, has on puberty, fertility, pregnancy, and parturition in dogs. Ideal body condition at puberty is necessary for dogs to achieve sexual maturity and reproduce. Moreover, over and under conditioned female dogs have increased risk of adverse pregnancy, parturition, and neonatal outcomes. Less is known about body condition and male dog fertility but some evidence is provided in this article. Finally, recommendations for maintaining an ideal body condition in intact adult dogs for optimal fertility are provided.

Associations between Maternal Nutrition and the Concentrations of Human Milk Oligosaccharides in a Cohort of Healthy Australian Lactating Women

Human milk oligosaccharides (HMOs) are complex glycans associated with positive infant health outcomes. The concentrations of HMOs in the milk of lactating women are associated with substantial intra- and inter-individual differences and may be influenced by maternal physiological and/or nutrition-related factors. The primary aim of this study was to explore potential influences of short-term maternal diet and current body composition on HMO profiles in mature human milk. Milk samples were collected at 3-4 months postpartum from 101 healthy Australian women using standardised procedures, and analysed for macronutrients (lactose, fat, and protein). In addition, HMO concentrations were analysed using liquid-chromatography mass-spectrometry (LC-MS). Maternal dietary data were collected using three validated 24-h dietary recalls, and the body composition of a subgroup of mothers was assessed by DEXA scans (n = 30). Most (79%) of the women were secretor-positive. Individual nutrients were not significantly correlated with HMO concentrations after correction for multiple comparisons (p > 0.05), except for dietary folate intake. DEXA scans revealed no associations between HMO profiles and maternal body composition during established lactation. The study findings suggest a lack of clear and consistent associations between maternal nutrition and HMO concentrations in mature human milk from healthy lactating women with adequate dietary intake. The prevailing influence of genetic variation in lactating mothers may overshadow any impact of maternal nutritional and/or physiological status on HMO composition in mature human milk.

Parental factors that impact the ecology of human mammary development, milk secretion, and milk composition-a report from "Breastmilk Ecology: Genesis of Infant Nutrition (BEGIN)" Working Group 1

The goal of Working Group 1 in the Breastmilk Ecology: Genesis of Infant Nutrition (BEGIN) Project was to outline factors influencing biological processes governing human milk secretion and to evaluate our current knowledge of these processes. Many factors regulate mammary gland development in utero, during puberty, in pregnancy, through secretory activation, and at weaning. These factors include breast anatomy, breast vasculature, diet, and the lactating parent's hormonal milieu including estrogen, progesterone, placental lactogen, cortisol, prolactin, and growth hormone. We examine the effects of time of day and postpartum interval on milk secretion, along with the role and mechanisms of lactating parent-infant interactions on milk secretion and bonding, with particular attention to the actions of oxytocin on the mammary gland and the pleasure systems in the brain. We then consider the potential effects of clinical conditions including infection, pre-eclampsia, preterm birth, cardiovascular health, inflammatory states, mastitis, and particularly, gestational diabetes and obesity. Although we know a great deal about the transporter systems by which zinc and calcium pass from the blood stream into milk, the interactions and cellular localization of transporters that carry substrates such as glucose, amino acids, copper, and the many other trace metals present in human milk across plasma and intracellular membranes require more research. We pose the question of how cultured mammary alveolar cells and animal models can help answer lingering questions about the mechanisms and regulation of human milk secretion. We raise questions about the role of the lactating parent and the infant microbiome and the immune system during breast development, secretion of immune molecules into milk, and protection of the breast from pathogens. Finally, we consider the effect of medications, recreational and illicit drugs, pesticides, and endocrine-disrupting chemicals on milk secretion and composition, emphasizing that this area needs much more research attention.

Determinants of human milk oligosaccharides profiles of participants in the STRONG kids 2 cohort

Introduction

Human milk oligosaccharides (HMOS) are indigestible carbohydrates that support infant development by establishing a healthy microbiota, preventing infectious diseases, and promoting immune and cognitive development. Individual HMOS have distinct functions based on their chemical structures. HMO profiles can vary largely among mothers, but the research on factors other than genetic background affecting HMO composition are limited.

Methods

In the present analysis, we examined the relationships between maternal characteristics and the HMO profiles of breastfeeding mothers (n = 392) in the STRONG kids 2 with the following demographic characteristics: average age: 30.8 y, 74.5% White, and 75.5% exclusively breastfeeding. Human milk samples were collected at 6 weeks postpartum and maternal information was obtained from self-reported surveys. Information on dietary intake changes since the participants have been breastfeeding was collected. HMO profiles were analyzed by high performance liquid chromatography coupled with mass spectrometry and secretor status was determined by the presence of four secretor markers [2′-fucosyllactose (2′-FL), LNFP I, LDFT, and TFLNH]. Spearmen correlation test was utilized to determine the relationships between individual HMOS and associations with maternal factors. Between-group differences in HMO relative abundances were examined with Kruskal-Wallis test.

Results

Among all participants, 71.9% were secretors and 28.1% were non-secretors. The relative abundances of all HMOS differed (p &lt; 0.05) by secretor status, with the exception for 6′-SL and 3′-SL. Positive correlations were observed among HMOS with similar structures, such as the 1,2-fucosylated HMOS. The abundances of selected HMOS were associated with maternal body weight, pregnancy complications, and dietary characteristics. Based on pre-pregnancy BMI, in all mothers, relative abundance of 3′-SL was significantly higher in overweight mothers than obese mothers (p = 0.013). In milk produced by non-secretor mothers, LNPF I + III abundances were greater in overweight than normal weight mothers (p = 0.020). Several HMO abundances were found to be associated with Gestational diabetes mellitus (GDM). Variations of HMO abundances were also observed with dietary food intake. In all mothers, egg consumption was positively correlated with LNT + LNnT (R = 0.13; p = 0.012) and cheese intake was positively associated with 2′-FL (R = 0.10; p = 0.046) and S-LNnH II (R = 0.11; p = 0.026) abundances.

Discussion

HMO profiles were found to be associated with maternal characteristics and intake. Future research will investigate associations between HMOS and maternal and infant outcomes.

Maternal weight, gut microbiota, and the association with early childhood behavior: the PREOBE follow-up study

BACKGROUND AND AIM

Maternal overweight and breastfeeding seem to have a significant impact on the gut microbiota colonization process, which co-occurs simultaneously with brain development and the establishment of the "microbiota-gut-brain axis", which potentially may affect behavior later in life. This study aimed to examine the influence of maternal overweight, obesity and/or gestational diabetes on the offspring behavior at 3.5 years of age and its association with the gut microbiota already established at 18 months of life.

METHODS

156 children born to overweight (OV, n = 45), obese (OB, n = 40) and normoweight (NW, n = 71) pregnant women participating in the PREOBE study were included in the current analysis. Stool samples were collected at 18 months of life and gut microbiome was obtained by 16S rRNA gene sequencing. Behavioral problems were evaluated at 3.5 years by using the Child Behavior Checklist (CBCL). ANOVA, Chi-Square Test, ANCOVA, Spearman's correlation, logistic regression model and generalized linear model (GLM) were performed.

RESULTS

At 3.5 years of age, Children born to OV/OB mothers showed higher scores in behavioral problems than those born to NW mothers. Additionally, offspring born to OB mothers who developed gestational diabetes mellitus (GDM) presented higher scores in attention/deficit hyperactivity and externalizing problems than those born to GDM OV/NW mothers. Fusicatenibacter abundance found at 18 months of age was associated to lower scores in total, internalizing and pervasive developmental problems, while an unidentified genus within Clostridiales and Flavonifractor families abundance showed a positive correlation with anxiety/depression and somatic complaints, respectively. On the other hand, children born to mothers with higher BMI who were breastfed presented elevated anxiety, internalizing problems, externalizing problems and total problems scores; likewise, their gut microbiota composition at 18 months of age showed positive correlation with behavioral problems at 3.5 years: Actinobacteria abundance and somatic complaints and between Fusobacteria abundance and withdrawn behavior and pervasive developmental problems.

CONCLUSIONS

Our findings suggests that OV/OB and/or GDM during pregnancy is associated with higher behavioral problems scores in children at 3.5 years old. Additionally, associations between early life gut microbiota composition and later mental health in children was also found.

The Human Milk Metabolome: A Scoping Literature Review

BACKGROUND

Human milk is a complex source of nutrition and other bioactives that protects infants from disease, holding a lifetime of beneficial effects. The field of metabolomics provides a robust platform through which we can better understand human milk at a level rarely examined.

RESEARCH AIM

To Identify, describe, synthesize, and critically analyze the literature within the past 5 years related to the human milk metabolome.

METHODS

We conducted a scoping literature review and quality analysis of the recent science reflecting untargeted metabolomic approaches to examining human milk. We searched six databases using the terms "breast milk," "metabolome," "metabolite," and "human milk," Out of more than 1,069 abstracts, we screened and identified 22 articles that met our inclusion criteria.

RESULTS

We extracted data related to the study author, geographic location, research design, analyses, platform used, and results. We also extracted data related to human milk research activities, including collection protocol, infant/maternal considerations, and time. Selected studies focused on a variety of phenotypes, including maternal and infant disease. Investigators used varying approaches to evaluate the metabolome, and differing milk collection protocols were observed.

CONCLUSION

The human milk metabolome is informed by many factors-which may contribute to infant health outcomes-that have resulted in disparate milk metabolomic profiles. Standardized milk collection and storage procedures should be implemented to minimize degradation. Investigators may use our findings to develop research questions that test a targeted metabolomic approach.

lncRNA‑miRNA‑mRNA network in female offspring born from obese dams

Maternal obesity is associated with disturbance of lipid metabolism and obesity in offspring; however, the pathogenesis is still unclear. The present study elucidated the role of potential lipid metabolism-associated long non-coding RNA (lncRNA) and identified the pathways involved in mice born to obese dams. In the present study, maternal obesity was induced by feeding a high-fat diet for 10 weeks in female C57/BL6 mice, whereas control mice were fed a standard diet. All female mice mated with healthy male mice and were allowed to deliver spontaneously. The results demonstrated that female offspring from obese dams presented a tendency to become overweight in the first 8 weeks after birth; however, maternal obesity did not significantly alter the body weight of male offspring. RNA-sequencing analysis was performed on female offspring liver at 3 weeks old. Significantly dysregulated lncRNAs and downstream targets in female offspring liver were identified using bioinformatics analysis. lncRNA, microRNA (miRNA or miR) and mRNA expression levels in liver and AML12 cells were assessed using reverse transcription-quantitative PCR. A total of 8 upregulated and 17 downregulated lncRNAs were demonstrated in offspring from obese dams and lncRNA Lockd was indicated to be a key dysregulated lncRNA. Competing endogenous RNA (ceRNA) models suggested that the lncRNA Lockd/miR-582-5p/Elovl5 pathway was key for lipid metabolism in the liver of offspring from obese dams. Finally, small interfering RNA and miRNA inhibitor transfection was used to evaluate the ceRNA models in AML12 cells. Taken together, the results of the present study indicated that lncRNA Lockd-miR-582-5p-Elovl5 network may be disrupted in lipid metabolism and lead to obesity in the offspring of obese dams. This research will provide new insights into the molecular mechanism of obesity and lipid metabolism disorder.

Maternal Pea Protein Intake Provides Sex-Specific Protection against Dyslipidemia in Offspring from Obese Pregnancies

Increased consumption of dietary pulse protein has been shown to assist in body weight regulation and improve a range of metabolic health outcomes. We investigated if the exchange of casein for yellow pea protein (YPPN) in an obese-inducing maternal diet throughout pregnancy and lactation offered protection against obesity and dyslipidemia in offspring. Sixty female Sprague Dawley rats were fed a low-calorie control diet (CON), a high-caloric obesity-inducing diet (with casein protein (CP), HC-CP), or an isocaloric/macronutrient-matched HC diet supplemented with YPPN isolate (HC-PPN) in pre-pregnancy, gestation, and lactation. Body weight (BW) and metabolic outcomes were assessed in male and female offspring at weaning and in adulthood after consuming the CON diet in the postnatal period. Consumption of the HC-PPN diet did not protect against maternal obesity but did improve reproductive success compared with the HC-CP group (72.7% versus 43.7%) and reduced total energy, fat, and protein in maternal milk. Male, but not female, offspring from mothers fed the HC-CP diet demonstrated hyperphagia, obesity, dyslipidemia, and hepatic triglyceride (TG) accumulation as adults compared with CON offspring. Isocaloric exchange of CP for YPPN in a high-calorie obese-inducing diet did not protect against obesity but did improve several aspects of lipid metabolism in adult male offspring including serum total cholesterol, LDL/VLDL cholesterol, triglycerides (TGs), and hepatic TG concentration. Our results suggest that the exchange of CP for YPPN in a maternal obese-inducing diet selectively protects male offspring from the malprogramming of lipid metabolism in adulthood.

Metabolomics can provide new insights into perinatal nutrition

Perinatal nutrition is a key factor related to the Developmental Origin of Health and Disease hypothesis, which states that each and every event that happens during the periconceptional period and pregnancy can affect the health status of an individual. Metabolomics can be a very useful tool for gathering information about the effect of perinatal nutrition on both mothers and newborn infants. This non-systematic review focuses on the main metabolites detected by this technique, with regard to gestational diabetes, intrauterine growth restriction and breast milk. Conclusion. Nutrition, metabolome and microbiome interactions are gaining interest in the scientific community.

Influence of Perinatal Factors on Gene Expression of IAPs Family and Main Factors of Pluripotency: OCT4 and SOX2 in Human Breast Milk Stem Cells-A Preliminary Report

Due to their therapeutic potential, mesenchymal stem cells are the subject of intensive research on the use of their potential in the treatment of, among others, neurodegenerative diseases or immunological diseases. They are among the newest in the field of medicine. The presented study aimed to evaluate the expression of eight genes from the IAP family and the gene regulating IAP-XAF1-in stem cells derived from human milk, using the qPCR method. The relationships between the expression of genes under study and clinical data, such as maternal age, maternal BMI, week of pregnancy in which the delivery took place, bodyweight of the newborn, the number of pregnancies and deliveries, and the time elapsed since delivery, were also analyzed. The research was carried out on samples of human milk collected from 42 patients hospitalized in The Clinic of Obstetrics and Perinatology of the Independent Public Clinical Hospital No. 4, in Lublin. The conducted research confirmed the expression of the following genes in the tested material: NAIP, BIRC2, BIRC3, BIRC5, BIRC6, BIRC8, XIAP, XAF1, OCT4 and SOX2. Moreover, several dependencies of the expression of individual genes on the maternal BMI (BIRC5, XAF1 and NAIP), the time since childbirth (BIRC5, BIRC6, XAF1 and NAIP), the number of pregnancies and deliveries (BIRC2, BIRC5, BIRC6 and XAF1), the manner of delivery (XAF1 and OCT4), preterm labor (BIRC6 and NAIP) were demonstrated. Additionally, we found positive relationships between gene expression of BIRC7, BIRC8 and XAF1 and the main factors of pluripotency: SOX2 and OCT4. This work is the first to investigate the expression of genes from the IAPs family in mother's milk stem cells.

Human milk variation is shaped by maternal genetics and impacts the infant gut microbiome

Human milk is a complex mix of nutritional and bioactive components that provide complete nutrition for the infant. However, we lack a systematic knowledge of the factors shaping milk composition and how milk variation influences infant health. Here, we used multi-omic profiling to characterize interactions between maternal genetics, milk gene expression, milk composition, and the infant fecal microbiome in 242 exclusively breastfeeding mother-infant pairs. We identified 487 genetic loci associated with milk gene expression unique to the lactating mammary gland, including loci that impacted breast cancer risk and human milk oligosaccharide concentration. Integrative analyses uncovered connections between milk gene expression and infant gut microbiome, including an association between the expression of inflammation-related genes with IL-6 concentration in milk and the abundance of Bifidobacteria in the infant gut. Our results show how an improved understanding of the genetics and genomics of human milk connects lactation biology with maternal and infant health.

Revisiting One-Carbon Metabolites in Human Breast Milk: Focus on S-Adenosylmethionine

Breastfeeding is the gold standard for early nutrition. Metabolites from the one-carbon metabolism pool are crucial for infant development. The aim of this study is to compare the breast-milk one-carbon metabolic profile to other biofluids where these metabolites are present, including cord and adult blood plasma as well as cerebrospinal fluid. Breast milk (n = 142), cord blood plasma (n = 23), maternal plasma (n = 28), aging adult plasma (n = 91), cerebrospinal fluid (n = 92), and infant milk formula (n = 11) samples were analyzed by LC-MS/MS to quantify choline, betaine, methionine, S-adenosylmethionine, S-adenosylhomocysteine, total homocysteine, and cystathionine. Differences between groups were visualized by principal component analysis and analyzed by Kruskal-Wallis test. Correlation analysis was performed between one-carbon metabolites in human breast milk. Principal component analysis based on these metabolites separated breast milk samples from other biofluids. The S-adenosylmethionine (SAM) concentration was significantly higher in breast milk compared to the other biofluids and was absent in infant milk formulas. Despite many significant correlations between metabolites in one-carbon metabolism, there were no significant correlations between SAM and methionine or total homocysteine. Together, our data indicate a high concentration of SAM in breast milk, which may suggest a strong demand for this metabolite during infant early growth while its absence in infant milk formulas may indicate the inadequacy of this vital metabolic nutrient.

The associations of maternal and paternal obesity with latent patterns of offspring BMI development between 7 and 17 years of age: pooled analyses of cohorts born in 1958 and 2001 in the United Kingdom

OBJECTIVE

We aimed to 1) describe how the UK obesity epidemic reflects a change over time in the proportion of the population demonstrating adverse latent patterns of BMI development and 2) investigate the potential roles of maternal and paternal BMI in this secular process.

METHODS

We used serial BMI data between 7 and 17 years of age from 13220 boys and 12711 girls. Half the sample was born in 1958 and half in 2001. Sex-specific growth mixture models were developed. The relationships of maternal and paternal BMI and weight status with class membership were estimated using the 3-step BCH approach, with covariate adjustment.

RESULTS

The selected models had five classes. For each sex, in addition to the two largest normal weight classes, there were "normal weight increasing to overweight" (17% of boys and 20% of girls), "overweight increasing to obesity" (8% and 6%), and "overweight decreasing to normal weight" (3% and 6%) classes. More than 1-in-10 children from the 2001 birth cohort were in the "overweight increasing to obesity" class, compared to less than 1-in-30 from the 1958 birth cohort. Approximately 75% of the mothers and fathers of this class had overweight or obesity. When considered together, both maternal and paternal BMI were associated with latent class membership, with evidence of negative departure from additivity (i.e., the combined effect of maternal and paternal BMI was smaller than the sum of the individual effects). The odds of a girl belonging to the "overweight increasing to obesity" class (compared to the largest normal weight class) was 13.11 (8.74, 19.66) times higher if both parents had overweight or obesity (compared to both parents having normal weight); the equivalent estimate for boys was 9.01 (6.37, 12.75).

CONCLUSIONS

The increase in obesity rates in the UK over more than 40 years has been partly driven by the growth of a sub-population demonstrating excess BMI gain during adolescence. Our results implicate both maternal and paternal BMI as correlates of this secular process.

Neonatal intake of Omega-3 fatty acids enhances lipid oxidation in adipocyte precursors

Establishing metabolic programming begins during fetal and postnatal development, and early-life lipid exposures play a critical role during neonatal adipogenesis. We define how neonatal consumption of a low omega-6 to -3 fatty acid ratio (n6/n3 FA ratio) establishes FA oxidation in adipocyte precursor cells (APCs) before they become adipocytes. In vivo, APCs isolated from mouse pups exposed to the low n6/n3 FA ratio had superior FA oxidation capacity, elevated beige adipocyte mRNAs Ppargc1α, Ucp2, and Runx1, and increased nuclear receptor NR2F2 protein. In vitro, APC treatment with NR2F2 ligand-induced beige adipocyte mRNAs and increased mitochondrial potential but not mass. Single-cell RNA-sequencing analysis revealed low n6/n3 FA ratio yielded more mitochondrial-high APCs and linked APC NR2F2 levels with beige adipocyte signatures and FA oxidation. Establishing beige adipogenesis is of clinical relevance, because fat depots with energetically active, smaller, and more numerous adipocytes improve metabolism and delay metabolic dysfunction.

Modulation of Milk and Lipid Synthesis and Secretion in a3-Dimensional Mouse Mammary Epithelial Cell Culture Model: Effects of Palmitate and Orlistat

Human milk synthesis is impacted by maternal diet, serum composition, and substrate uptake and synthesis by mammary epithelial cells (MECs). The milk of obese/high-fat-diet women has an increased fat content, which promote excess infant weight gain and the risk of childhood/adult obesity. Yet, the knowledge of milk synthesis regulation is limited, and there are no established approaches to modulate human milk composition. We established a 3-dimensional mouse MEC primary culture that recreates the milk production pathway and tested the effects of the major saturated fatty acid in human milk (palmitate) and a lipoprotein lipase inhibitor (orlistat) on triglyceride production. Positive immunostaining confirmed the presence of milk protein and intracellular lipid including milk globules in the cytoplasm and extracellular space. The treatment with palmitate activated "milk" production by MECs (β-casein) and the lipid pathway (as evident by increased protein and mRNA expression). Consistent with these cellular changes, there was increased secretion of milk protein and triglyceride in MEC "milk". The treatment with orlistat suppressed milk triglyceride production. Palmitate increased milk and lipid synthesis, partly via lipoprotein lipase activation. These findings demonstrate the ability to examine MEC pathways of milk production via both protein and mRNA and to modulate select pathways regulating milk composition in MEC culture.

Influence of maternal body mass index on human milk composition and associations to infant metabolism and gut colonisation: MAINHEALTH - a study protocol for an observational birth cohort

INTRODUCTION

Human milk provides all macronutrients for growth, bioactive compounds, micro-organisms and immunological components, which potentially interacts with and primes infant growth and, development, immune responses and the gut microbiota of the new-born. Infants with an overweight mother are more likely to become overweight later in life and overweight has been related to the gut microbiome. Therefore, it is important to investigate the mother-milk-infant triad as a biological system and if the maternal weight status influences the human milk composition, infant metabolism and gut microbiome.

METHODS AND ANALYSIS

This study aims to include 200 mother-infant dyads stratified into one of three body mass index (BMI) categories based on mother's prepregnancy BMI. Multiomics analyses include metabolomics, proteomics, glycomics and microbiomics methods, aiming to characterise human milk from the mothers and further relate the composition to infant gut microbiota and its metabolic impact in the infant. Infant gut microbiota is analysed using 16S sequencing of faeces samples. Nuclear magnetic resonance and mass spectrometry are used for the remaining omics analysis. We investigate whether maternal pre-pregnancy BMI results in a distinct human milk composition that potentially affects the initial priming of the infant's gut environment and metabolism early in life.

ETHICS AND DISSEMINATION

The Central Denmark Region Committees on Health Research Ethics has approved the protocol (J-nr. 1-10-72-296-18). All participants have before inclusion signed informed consent and deputy informed consent in accordance with the Declaration of Helsinki II. Results will be disseminated to health professionals including paediatricians, research community, nutritional policymakers, industry and finally the public. The scientific community will be informed via peer-reviewed publications and presentations at scientific conferences, the industry will be invited for meetings, and the public will be informed via reports in science magazines and the general press. Data cleared for personal data, will be deposited at public data repositories.

TRIAL REGISTRATION NUMBER

Danish regional committee of the Central Jutland Region, journal number: 1-10-72-296-18, version 6.Danish Data Protection Agency, journal number: 2016-051-000001, 1304.

CLINICALTRIALS

gov, identifier: NCT05111990.

Nutritional Programming: History, Hypotheses, and the Role of Prenatal Factors in the Prevention of Metabolic Diseases-A Narrative Review

Childhood obesity and the numerous lifestyle diseases associated with it are undoubtedly among the key problems in modern medicine and public health. However, this problem concerns not only the present or immediate future, but also the longer term. Adult health is fundamentally shaped in the first years of life and in the fetal period. The preconceptual period, which is responsible for the proper preparation of the internal environment for the life and development of the fetus during pregnancy, is also significant. A special role in describing the phenomenon of conditioning the metabolism of the new human being is now attributed to the theory of nutritional programming. Research in this area was pioneered by David Barker, who put forward the theory of the “stunted phenotype” and described the relationship between a child’s birth weight, which is largely a consequence of the mother’s feeding behaviour, and diseases such as ischaemic heart disease, type 2 diabetes (T2D), dyslipidemia, or high blood pressure. This narrative review aims to provide an overview of the history, theory, and prenatal mechanisms involved in nutritional programming and its relationship to childhood obesity and other metabolic diseases.

Milk Exosomal microRNAs: Postnatal Promoters of β Cell Proliferation but Potential Inducers of β Cell De-Differentiation in Adult Life

Pancreatic β cell expansion and functional maturation during the birth-to-weaning period is driven by epigenetic programs primarily triggered by growth factors, hormones, and nutrients provided by human milk. As shown recently, exosomes derived from various origins interact with β cells. This review elucidates the potential role of milk-derived exosomes (MEX) and their microRNAs (miRs) on pancreatic β cell programming during the postnatal period of lactation as well as during continuous cow milk exposure of adult humans to bovine MEX. Mechanistic evidence suggests that MEX miRs stimulate mTORC1/c-MYC-dependent postnatal β cell proliferation and glycolysis, but attenuate β cell differentiation, mitochondrial function, and insulin synthesis and secretion. MEX miR content is negatively affected by maternal obesity, gestational diabetes, psychological stress, caesarean delivery, and is completely absent in infant formula. Weaning-related disappearance of MEX miRs may be the critical event switching β cells from proliferation to TGF-β/AMPK-mediated cell differentiation, whereas continued exposure of adult humans to bovine MEX miRs via intake of pasteurized cow milk may reverse β cell differentiation, promoting β cell de-differentiation. Whereas MEX miR signaling supports postnatal β cell proliferation (diabetes prevention), persistent bovine MEX exposure after the lactation period may de-differentiate β cells back to the postnatal phenotype (diabetes induction).

Dynamic Changes in the Human Milk Metabolome Over 25 Weeks of Lactation

Human milk (HM) provides essential nutrition for ensuring optimal infant growth and development postpartum. Metabolomics offers insight into the dynamic composition of HM. Studies have reported the impact of lactation stage, maternal genotype, and gestational age on HM metabolome. However, the majority of the studies have considered changes within the first month of lactation or sampled with large intervals. This leaves a gap in the knowledge of progressing variation in HM composition beyond the first month of lactation. The objective of this study was to investigate whether the HM metabolome from mothers with term deliveries varies beyond 1 month of lactation, during the period in which HM is considered fully mature. Human milk samples (n = 101) from 59 mothers were collected at weeks 1–2, 3–5, 7–9, and 20–25 postpartum and analyzed using ¹H nuclear magnetic resonance spectroscopy. Several metabolites varied over lactation and exhibited dynamic changes between multiple time points. Higher levels of HM oligosaccharides, cis-aconitate, O-phosphocholine, O-acetylcarnitine, gluconate, and citric acid were observed in early lactation, whereas later in lactation, levels of lactose, 3-fucosyllactose, glutamine, glutamate, and short- and medium-chain fatty acids were increased. Notably, we demonstrate that the HM metabolome is dynamic during the period of maturity.

Bioactive compounds in mothers milk affecting offspring outcomes: A narrative review

BACKGROUND

Compared to the exhaustive study of transgenerational programming of obesity and diabetes through exposures in the prenatal period, postnatal programming mechanisms are understudied, including the potential role of breast milk composition linking maternal metabolic status (body mass index and diabetes) and offspring growth, metabolic health and future disease risk.

METHODS

This narrative review will principally focus on four emergent bioactive compounds [microRNA's (miRNA), lipokines/signalling lipids, small molecules/metabolites and fructose] that, until recently were not known to exist in breast milk. The objective of this narrative review is to integrate evidence across multiple fields of study that demonstrate the importance of these compositional elements of breast milk during lactation and the subsequent effect of breast milk components on the health of the infant.

RESULTS

Current knowledge on the presence of miRNA's, lipokines/signalling lipids, small molecules/metabolites and fructose in breast milk and their associations with infant outcomes is compelling, but far from resolved. Two themes emerge: (1) maternal metabolic phenotypes are associated with these bioactives and (2) though existing in milk at low concentrations, they are also associated with offspring growth and body composition.

CONCLUSION

Breast milk research is gaining momentum though we must remain focused on understanding how non-nutritive bioactive components are affected by the maternal phenotype, how they subsequently impact infant outcomes. Though early, there is evidence to suggest fructose is associated with fat mass in the 1st months of life whereas 12,13 diHOME (brown fat activator) and betaine are negatively associated with early adiposity and growth.

The association of pre-pregnancy BMI on leptin, ghrelin, adiponectin and insulin-like growth factor-1 in breast milk: a case-control study

The nutrient composition of breast milk alters during lactation, and maternal BMI adds more intricacy into its complexity. We aimed to compare leptin, ghrelin, adiponectin and insulin-like growth factor-1 (IGF-1) levels of pre-feed and post-feed breast milk in mothers with obesity and normal weight, and tried to determine their effects on infants' growth over weight for length z-score. Twenty obese and twenty normal weight mothers with 2-month-old infants were enrolled in this case-control study. Five millilitre pre-feed breast milk and 5 ml post-feed breast milk were collected. Breast milk leptin, ghrelin, adiponectin and IGF-1 were measured by commercial kits. The pre-feed breast milk of mothers with obesity had significantly higher levels of ghrelin than mothers with normal weight (P = 0·025), whereas the post-feed breast milk of mothers with normal weight had higher levels of adiponectin than the mothers with obesity (P = 0·010). No significant differences were observed in leptin and IGF-1 levels between the two groups. Post-feed breast milk IGF-1 levels of mothers with obesity were correlated with infant's weight for length z-score at 2 months (r -0·476; P = 0·034). In linear regression models, parity affected the ghrelin in pre-feed breast milk (P = 0·025). Our results revealed that maternal pre-pregnancy BMI was associated with breast milk components.

Beyond the BMI: Validity and Practicality of Postpartum Body Composition Assessment Methods during Lactation: A Scoping Review

The assessment of body composition during lactation is an important indicator of maternal nutritional status, which is central to the overall health of the mother and child. The lactating woman’s nutritional status potentially impacts on breastmilk composition and the process of lactation itself. The purpose of this scoping review was to synthesize comparative studies that sought to validate various body composition assessment techniques for use in lactating women in the postpartum period. Using the PRISMA-ScR guidelines, a comprehensive, systematic literature search was conducted using Scopus, Web of Science, and PubMed. Eight comparative studies were included in the review, with data from 320 postpartum women. The design methodologies varied substantially across studies, and included a range of simple techniques to advanced multi-compartment models for assessing body composition. The validity and reliability of measurement tools must be considered alongside issues of safety, practicality, and appropriateness to guide the research design when applied to lactating women.

Human Milk Oligosaccharides Are Present in Amniotic Fluid and Show Specific Patterns Dependent on Gestational Age

(1) Background: Human milk oligosaccharides (HMOs) are already found in maternal circulation in early pregnancy, changing with gestational age. HMOs are also present in cord blood and amniotic fluid (AF). We aimed to assess HMO profiles in AF over the course of gestation. (2) Methods: AF was collected during diagnostic amniocentesis, fetal surgery, or C-section from 77 women with a gestational age of ranging from 14.3 to 40.9 weeks. Samples were analysed using high performance liquid chromatography with fluorescence detection. (3) Results: We found lactose and up to 16 HMO structures in all AF samples investigated, starting at 14 weeks of gestation. Overall, 3′-sialyllactose (3′SL) and 2′-fucosyllactose (2′FL) were the most abundant HMOs. Individual and total HMO concentrations were significantly positively correlated with gestational age. HMO composition also changed between early, mid- and late pregnancy, with relative concentrations of 3′SL significantly decreasing (44%, 25%, 24%) and 2′FL increasing (7%, 13%, 21%), respectively. (4) Conclusion: Our study shows that HMOs are already present in AF early in pregnancy. This demonstrates extensive contact of the fetus with a broad variety of HMOs, suggesting roles for HMOs in fetal tissue development during the time course of pregnancy.

Weighted analysis of 2'-fucosylactose, 3-fucosyllactose, lacto-N-tetraose, 3'-sialyllactose, and 6'-sialyllactose concentrations in human milk

Over 150 human milk oligosaccharides (HMOs) have been identified and their concentrations in human milk vary depending on Secretor and Lewis blood group status, environmental and geographical factors, lactation stage, gestational period, and maternal health. Quantitation of HMOs in human milk has been the focus of numerous studies, however, comprehensive and weighted statistical analyses of their levels in human milk are lacking. Therefore, weighted means, standard deviations, medians, interquartile ranges, and 90th percentiles for 2'-fucosyllactose (2'-FL), 3-fucosyllactose (3-FL), lacto-N-tetraose (LNT), 3'-sialyllactose (3'-SL) and 6'-sialyllactose (6'-SL) were calculated using random sampling and the levels of these HMOs in human milk reported in the literature. Probability distributions of the reported levels were also constructed. Although the levels reported in the published studies varied, the weighted means for 2'-FL, 3-FL, LNT, 3'-SL, and 6'-SL were calculated to be 2.58, 0.57, 0.94, 0.28, and 0.39 g/L, respectively, which are consistent with those that have been previously determined in other systematic analyses. Likely due to the use of weighting, the 90th percentiles were greater than the 95% confidence limits that have been previously calculated. Our study therefore provides accurate and important statistical data to help support the level of appropriate HMO supplementation in infant formula.

Maternal Factors Affecting the Macronutrient Composition of Transitional Human Milk

This study investigated the influence of selected maternal factors on the macronutrient composition and energy of human milk (HM). The study enrolled 159 breastfeeding mothers from five postpartum care centers in Seoul, Korea. Their gestational weeks were 37−42 weeks, they had no complications before and after childbirth, and were at 7−14 days postpartum. They provided data using structured questionnaires on general characteristics, stress, sleep quality, spousal support, and dietary intake. Breastfeeding assessment (LATCH) was investigated by qualified nurses, and each mother provided one sample of HM. The HM composition was analyzed using the Miris® HM analyzer. The relationships between variables were analyzed using Pearson’s correlation analysis, and a linear regression analysis was performed to verify the main variables. It was found that maternal dietary intake was related to HM composition as the %energy from carbohydrates (β = 0.86, p < 0.01) and %energy from fat (β = 0.77, p < 0.05) showed positive relationships with HM energy. The LATCH score was positively related to HM energy (β = 0.17, p < 0.05). In contrast, postpartum stress, sleep quality, and spousal support were not associated with HM macronutrient composition. In conclusion, HM macronutrients and energy content were associated with maternal dietary intake and LATCH scores, but not with postpartum stress, sleep quality, and spousal support.

Human Milk Oligosaccharides and Bacterial Profile Modulate Infant Body Composition during Exclusive Breastfeeding

Human milk is a complex and variable ecosystem fundamental to the development of newborns. This study aimed to investigate relationships between human milk oligosaccharides (HMO) and human milk bacterial profiles and infant body composition. Human milk samples (n = 60) were collected at two months postpartum. Infant and maternal body composition was measured with bioimpedance spectroscopy. Human milk bacterial profiles were assessed using full-length 16S rRNA gene sequencing and 19 HMOs were quantitated using high-performance liquid chromatography. Relative abundance of human milk bacterial taxa were significantly associated with concentrations of several fucosylated and sialylated HMOs. Individual human milk bacteria and HMO intakes and concentrations were also significantly associated with infant anthropometry, fat-free mass, and adiposity. Furthermore, when data were stratified based on maternal secretor status, some of these relationships differed significantly among infants born to secretor vs non-secretor mothers. In conclusion, in this pilot study the human milk bacterial profile and HMO intakes and concentrations were significantly associated with infant body composition, with associations modified by secretor status. Future research designed to increase the understanding of the mechanisms by which HMO and human milk bacteria modulate infant body composition should include intakes in addition to concentrations.

NMR Metabonomic Profile of Preterm Human Milk in the First Month of Lactation: From Extreme to Moderate Prematurity

Understanding the composition of human milk (HM) can provide important insights into the links between infant nutrition, health, and development. In the present work, we have longitudinally investigated the metabolome of milk from 36 women delivering preterm at different gestational ages (GA): extremely (<28 weeks GA), very (29–31 weeks GA) or moderate (32–34 weeks GA) premature. Milk samples were collected at three lactation stages: colostrum (3–6 days post-partum), transitional milk (7–15 days post-partum) and mature milk (16–26 days post-partum). Multivariate and univariate statistical data analyses were performed on the ¹H NMR metabolic profiles of specimens in relation to the degree of prematurity and lactation stage. We observed a high impact of both the mother’s phenotype and lactation time on HM metabolome composition. Furthermore, statistically significant differences, although weak, were observed in terms of GA when comparing extremely and moderately preterm milk. Overall, our study provides new insights into preterm HM metabolome composition that may help to optimize feeding of preterm newborns, and thus improve the postnatal growth and later health outcomes of these fragile patients.

Analgesic Effects of Epidural Labor Analgesia at Different Periods and Its Effects on Maternal and Infant Outcomes and MiRNA-146b Level

This paper aimed to analyze the analgesic effects of continuous epidural labor analgesia (ELA) at different periods and its effects on postpartum depression, maternal and infant outcomes, and maternal blood pressure. Giving birth in our hospital from September 2017 to August 2019, 119 primiparas with spontaneous delivery were enrolled and divided into an observation group (65 cases) and a control group (54 cases). Patients in the observation group received epidural block analgesia in advance, whereas those in the control group received epidural block analgesia routinely. At 25 days after delivery, breast milk samples were collected, in which miRNA-146b level was detected by PCR. The patients were compared between the two groups with respect to progress of labor, analgesic effects during 3 stages of labor, labor outcomes, adverse reactions, and levels of NO, ANP, and ET-1 in the parturients' umbilical artery blood. Compared with those in the control group, patients in the observation group had a remarkably higher miRNA-146b level in the breast milk (P < 0.05), remarkably lower average Visual Analogue Scale (VAS) scores during the active phase and the second stage of labor (P < 0.05), and remarkably higher levels of NO, ANP, and ET-1 (P < 0.05). There were no statistically significant differences in adverse reactions and modes of delivery between the two groups (P < 0.05). ELA starting from the latent phase can improve the miRNA-146b level in maternal breast milk, alleviate labor pain of parturients, and shorten stages of labor. Therefore, our study is worthy of clinical promotion. We still need to do more experiments and use more data to conclude more scientific results in future research work.

Studies and Application of Sialylated Milk Components on Regulating Neonatal Gut Microbiota and Health

Breast milk is rich in sialic acids (SA), which are commonly combined with milk oligosaccharides and glycoconjugates. As a functional nutrient component, SA-containing milk components have received increasing attention in recent years. Sialylated human milk oligosaccharides (HMOs) have been demonstrated to promote the growth and metabolism of beneficial gut microbiota in infants, bringing positive outcomes to intestinal health and immune function. They also exhibit antiviral and bacteriostatic activities in the intestinal mucosa of new-borns, thereby inhibiting the adhesion of pathogens to host cells. These properties play a pivotal role in regulating the intestinal microbial ecosystem and preventing the occurrence of neonatal inflammatory diseases. In addition, some recent studies also support the promoting effects of sialylated HMOs on neonatal bone and brain development. In addition to HMOs, sialylated glycoproteins and glycolipids are abundant in milk, and are also critical to neonatal health. This article reviews the current research progress in the regulation of sialylated milk oligosaccharides and glycoconjugates on neonatal gut microbiota and health.

Can breastfeeding affect the rest of our life?

The breastfeeding period is one of the most important critical windows in our development, since milk, our first food after birth, contains several compounds, such as macronutrients, micronutrients, antibodies, growth factors and hormones that benefit human health. Indeed, nutritional, and environmental alterations during lactation, change the composition of breast milk and induce alterations in the child's development, such as obesity, leading to the metabolic dysfunctions, cardiovascular diseases and neurobehavioral disorders. This review is based on experimental animal models, most of them in rodents, and summarizes the impact of an adequate breast milk supply in view of the developmental origins of health and disease (DOHaD) concept, which has been proposed by researchers in the areas of epidemiology and basic science from around the world. Here, experimental advances in understanding the programming during breastfeeding were compiled with the purpose of generating knowledge about the genesis of chronic noncommunicable diseases and to guide the development of public policies to deal with and prevent the problems arising from this phenomenon. This review article is part of the special issue on "Cross talk between periphery and brain".

Factors influencing the microbial composition of human milk

Aside from nutritional components, human milk is rich in microorganisms. Through breastfeeding these microorganisms are introduced to the infant gut where they may transiently or persistently colonize it. Therefore, the human milk microbiota may be an important factor which shapes the infant gut microbiota further influencing infant health and disease. In the current review we aim to give a brief updated insight into the putative origin of the human milk microbiota, its constituents and the possible factors that shape it. Understanding the factors that determine the human milk microbiota composition and function will aid developing optimal postnatal feeding and intervention strategies to reduce the risk of communicable and noncommunicable diseases.