Impact of maternal overweight and obesity on milk composition and infant growth

Perinatal leptin effects on hypothalamic brain-derived neurotrophic factor and energy balance-related gene regulation

Brain-derived neurotrophic factor (BDNF) and leptin are essential in neurodevelopment and central regulation of feeding and energy balance. We studied the metabolic imprinting effects of physiological leptin supplementation during suckling in the brain of 5-week-old mouse pups. Leptin-treated animals showed lower cumulative food intake and increased energy efficiency, which was related to higher lean mass. Among different brain areas, hypothalamic expression of Bdnf and upstream transcription control-related genes, such as Ppargc1a and Fndc5, was increased by leptin supplementation, especially in females. This was accompanied by higher expression of energy balance key genes (such as Prkaa2 and Cpt1c) and insulin/leptin signalling pathways, primarily in females, also with lower levels of total/phosphorylated AMPK, ACC or STAT3, mainly in males. In leptin-treated females, the exon IV Bdnf promoter showed increased methylation at a specific CpG site. Leptin supplementation during suckling can sex-dependently imprint hypothalamic gene expression, regulating the Ppargc1a/Fndc5/Bdnf pathway and related genes involved in energy balance, associated with a leaner phenotype, with a higher positive impact in females.

Maternal adiposity moderates associations between dietary, serum, and human milk n-3 and n-6 PUFA

Overweight and obesity can alter the composition of human milk, including the fatty acid (FA) profile into more proinflammatory state. It is uncertain whether this is due to poor diet quality or the negative effects of obesity on FA metabolism. We examined the associations between dietary, serum, and human milk FA in mothers with normal and excessive body weight and investigated whether adiposity moderates the observed associations. A case-control study was conducted among 40 mothers (20 healthy weight (HW), 20 overweight/obese (OW/OB) 15.5 ± 1.2 weeks postpartum, matched by lactation duration and age. Dietary intake was analyzed based on 3-day food records, and adiposity was assessed by dual-energy X-ray absorptiometry (DXA), serum and human milk FA analyzed by gas chromatography (GC). Overweight/obese mothers had higher dietary and serum trans FA but lower serum arachidonic acid (AA) and human milk docosahexaenoic acid (DHA) compared to normal-weight mothers. Mediation analysis indicated that serum partially mediated the effect of dietary linoleic acid (LA), polyunsaturated fatty acid (PUFA) n-3, and alpha-linolenic acid (ALA) on human milk FA. Adiposity were found to negatively impact the dietary-to-human milk FA association but positively impact serum-to-human milk association. The obesity-related differences in human milk FA profile were not due to dietary differences. Our results suggest human milk PUFA levels may be influenced more by long-term diet than short-term intake, indicating a need for specific dietary guidelines for mothers with higher adiposity to minimze proinflammatory alterations in human milk composition.

Determination of macronutrient profile and energy composition in human milk via Mid-Infrared Spectrometer Analysis: An experimental study

BACKGROUND

To study the effect of specific maternal and neonatal variables on the macronutrients and energy composition of expressed human milk samples.

METHODS

A prospective study was conducted including 296 samples of human milk delivered from 201 participant mothers. Human milk was analyzed using Mid-Infrared Spectrometer Analysis.

RESULTS

Colostrum exhibited significantly higher crude protein and lower fat, carbohydrate, total solids, and energy content compared with transitional or mature milk. Milk from mothers who were obese showed significantly higher total solids levels and energy, compared with milk from mothers who were overweight, or of normal weight. Milk from mothers of preterm infants had higher crude protein, and lower carbohydrate content, compared with that of full-term infants. Finally, significant differences were observed in fat, carbohydrate, total solids, and energy between extremely and very low, low, or normal birth weight infants. Maternal body mass index and the phase of lactation were significantly associated with crude protein, whereas pregnancy duration and birth weight were positively correlated with carbohydrates and negatively correlated with fat, total solids, and energy content.

CONCLUSION

Neonatal and maternal factors are associated with the macronutrients and energy content of expressed human milk samples. Further research is warranted to explore the specific preterm infants' nutrition needs.

Maternal Obesity and Excessive Gestational Weight Gain Influence Endocannabinoid Levels in Human Milk Across Breastfeeding: Potential Implications for Offspring Development

Background/Objectives: Endocannabinoids are endogenous bioactive lipids that promote neurodevelopment and positive energy balance. Increased levels of endocannabinoids are associated with obesity, but the effect of maternal obesity on breast milk endocannabinoids across lactation is mostly unknown. Methods: Women from Rio de Janeiro (Brazil) (n = 92) were followed from the third trimester of pregnancy to 119 days postpartum, and milk samples were analyzed in the postpartum days 2-8 (T1), 28-47 (T2), and 88-119 (T3). We assessed the endocannabinoids anandamide (AEA) and 2-arachidonoylglycerol (2-AG) by high-performance liquid chromatography-mass spectrometry, leptin and insulin by immunoassay, and macronutrients by colorimetric assays in milk samples. Results: Milk AEA concentration was higher in T2 compared with T1 or T3, while 2-AG levels were higher in T2 and T3 compared with T1. Milk endocannabinoids were directly correlated with pre-pregnancy body mass index (BMI), gestational weight gain (GWG), and milk triglycerides. Triglyceride and leptin levels were higher in mature milk (T2 and T3) of women with BMI > 25 or excessive GWG. Adjusted linear regression models showed a positive association between excessive GWG and milk 2-AG (β = 1629; 95% CI: 467-2792; p = 0.008). Conclusions: The endocannabinoid levels are higher in mature milk from women with obesity or excessive GWG, which may impact offspring development and metabolism.

The Associations of Maternal Prepregnancy Body Mass Index With Human Milk Fatty Acid and Phospholipid Composition in the Observational Norwegian Human Milk Study

BACKGROUND

Human milk fat quality depends on its fatty acid (FA) and phospholipid (PL) composition. There is clear evidence that maternal diet influences human milk FA composition. However, the scientific literature concerning associations between prepregnancy body mass index (pBMI) and milk FA and PL composition remains inconclusive.

OBJECTIVES

This observational study aimed to identify the associations between maternal pBMI and the milk FA and choline-containing PL species composition, considering study confounders, including fish intake as a proxy for n3 long-chain polyunsaturated FA (n3-LCPUFA).

METHODS

We analyzed total FA and choline-containing PL-classes (lysophosphatidylcholine, phosphatidylcholine, and sphingomyelin) in 628 milk samples from the Norwegian Human Milk Study birth-cohort using gas chromatography and flow-injection mass spectrometry, respectively. Multiple regression analysis assessed the relationship between pBMI and milk lipid metabolites (%FA, %PL) (reported as β = standardized regression coefficient with adjusted P value < 0.0005, B(95% confidence interval [CI]) = unstandardized coefficient with 95% CI).

RESULTS

Maternal pBMI showed significant association (P < 0.0005) with n3-LCPUFA [β = -0.138, B(95% CI) = -0.010 (-0.015, -0.005)], n6/n3LCPUFA ratio [β = 0.170, B(95% CI) = 0.020(0.012, 0.028)], monounsaturated FA [β = 0.207, B(95% CI) = 0.128(0.076, 0.180)], and corresponding PL species [%LysoPC16:1, β = 0.171, B(95% CI) = 0.001(0.001,0.002), %LysoPC18:1, β = 0.155, B(95%CI) = 0.005 (0.002,0.007)] adjusted with the study covariates. The percentages of variance explained by pBMI were 40% for the n6/n3 LCPUFA ratio, 34% for n3-LCPUFA, and 10% for monounsaturated FA. Conversely, analyses revealed no significant associations between pBMI and choline-containing PL classes.

CONCLUSIONS

Biological factors likely increased stearoyl-CoA desaturase activity, lower lipoprotein lipase activity, and a compensatory higher contribution of nonesterified FA from adipose tissue in mothers with pBMI ≥30 could potentially lead to the observed outcomes. Metabolic differences regarding BMI variances may influence the FA availability for mammary gland triglyceride and PL synthesis. Therefore, in addition to dietary intake, maintaining a healthy maternal pBMI may improve the nutritional quality of human milk, ultimately supporting infants' development.

Maternal obesity associates with altered humoral immunity in blood and colostrum

Maternal obesity is a condition with increasing prevalence worldwide, that correlates with negative infant outcomes. Here we performed an observational cross-sectional study, where peripheral blood and colostrum samples from 37 mothers with BMI between 18.5-25 or > 30 kg/m2 (21 and 16 mothers, respectively) were collected 24-48 h postpartum. B lymphocyte subpopulations were investigated using flow cytometry. IgG, IgA, and IgM concentrations, and antibody production from colostrum-resident B cells were quantified. Overall, naïve B lymphocytes were the most abundant subtype in peripheral blood, while CD27-IgD- double-negative B cells were the most frequent in colostrum. The colostrum from mothers with BMI > 30 kg/m2 contained significantly more IgG-secreting colostrum-resident B cells, more total IgG, and less total IgA. Mothers with BMI > 30 kg/m2 who had been vaccinated with the Pfizer BioNTech bivalent vaccine during the third trimester of pregnancy (n = 8) did not show higher IgA or IgG antibody responses against SARS-CoV-2 RBD in either tissue types compared to unvaccinated mothers, contrasting with mother of BMI between 18.5-25 kg/m2 (n = 7). This is the first characterization of B lymphocyte subpopulations and antibodies in the colostrum of mothers with obesity. This work uncovers maternal obesity as a possible modifier of humoral immune components in colostrum.

Breast Milk Macronutrient Content and Its Effects on Infant Anthropometric Measurements in the First 6 Months: A Systematic Review and Meta-Analysis

PURPOSE

The aim of the study is to determine the effect of the macronutrient content of breast milk on the anthropometric measurements of infants in the first 6 months.

BACKGROUND

Breast milk contains essential macro- and micronutrients needed in the early stages of an infant's development. Current literature highlights the importance of understanding how breast milk's macronutrient content influences infant growth.

METHODS

The study protocol has been published in PROSPERO (CRD42023425550). This study adheres to the Preferred Reporting Items for Systematic Review and Meta-Analysis Protocols (PRISMA-P) guideline. Studies published between January 1, 2016, and June 2, 2023, were reviewed across 6 databases. The Joanna Briggs Institute Cohort Studies checklist was used to assess methodological quality. Effect sizes were calculated using both fixed-effects and random-effects models.

RESULTS

Six studies were included in the systematic review and meta-analysis. The meta-analysis indicated a significant relationship between lactose content in breast milk and infant weight gain, length growth, and head circumference, as well as between fat-lipid content and infant weight gain within the first 6 months (P < .05). No significant relationship was found between protein or carbohydrate content of milk and anthropometric measurements of infants in the first 6 months (P > .05).

CONCLUSION AND IMPLICATIONS

The findings suggest that macronutrient concentrations in breast milk are important determinants of infant growth. Further research with high level of evidence and standard methodological protocols is recommended to elucidate the relationships between breast milk content and infant growth.

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

AIM

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.

BACKGROUND

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.

METHODS

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.

FINDINGS

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.

Investigating Leptin Gene Variants and Methylation Status in Relation to Breastfeeding and Preventing Obesity

Objective: We investigated whether the results of leptin gene (LEP) 2548G/A (rs7799039) and leptin receptor gene (LEPR) 668 A/G (rs1137101) variants, as well as the methylation analysis of CpG regions at nucleotides -31 and -51 of the LEP gene, showed any differences between breastfed and non-breastfed children in this study. Materials and Methods: The cross-sectional study included 100 children aged 2-5 years who were attending nursery and kindergarten and had been accepted to the Department of General Paediatrics. Infants who were exclusively breastfed for the first six months after birth constituted the study group, and those who were not only breastfeed constituted the control group. Methylation percentages at CpG islands of the LEP gene were compared between exclusively breastfed and non-exclusively breastfed infants, and the statistical significance was analyzed by looking for changes in LEP -31 and -51 nt methylation and LEP 2548G/A ve LEPR 668 A/G variants. Results: Both groups were compared by feeding, and the association of LEPR and LEP gene polymorphisms and -51 nt and -31 nt methylations were analyzed. There were no significant differences between the groups regarding genotype and allele frequency for the LEPR 668 A/G, LEP 2548 G/A gene variant, -31 nt methylation, and -51 nt methylation status. Similarly, there was no significant difference in genotype and allele frequency for the LEPR 668 A/G gene variant in terms of duration of exclusive breastfeeding, total breastfeeding, body mass index, family obesity, and satiety status. However, maternal support from family elders and physical activity increased the 51 nt methylation, but this methylation was not significantly affected by BMI, age, or satiety status. Conclusions: Maternal support from family elders and physical activity were associated with increased 51 nt methylation, but this methylation was not significantly affected by BMI, age, or satiety status. However, there are not enough studies in this area to reach a definitive conclusion, and further research is needed.

Analyzing the Responses of Enteric Bacteria to Neonatal Intensive Care Supplements

In the neonatal intensive care unit, adequate nutrition requires various enteral products, including human milk and formula. Human milk is typically fortified to meet increased calorie goals, and infants commonly receive vitamin mixes, iron supplements, and less frequently, thickening agents. We examined the growth of 16 commensal microbes and 10 pathobionts found in the premature infant gut and found that formula, freshly pasteurized milk, and donated banked milk generally increased bacterial growth. Fortification of human milk significantly elevated the growth of all microbes. Supplementation with thickeners or NaCl in general did not stimulate additional growth. Vitamin mix promoted the growth of several commensals, while iron promoted growth of pathobionts. These data indicate that pathobionts in the preterm gut have significant growth advantage with preterm formula, fortified donor milk, and supplemented iron and suggest that the choice of milk and supplements may impact the infant gut microbiota.

The association between maternal factors and milk hormone concentrations: a systematic review

Background

Breast milk is the gold standard for infant feeding. It is a dynamic biological fluid rich in numerous bioactive components. Emerging research suggests that these components, including hormones, may serve as signals between mother and offspring. From an evolutionary perspective, maternal hormonal signals could allow co-adaptation of maternal and offspring phenotype, with implications for their Darwinian fitness. However, a series of steps need to be considered to establish the role of a component as a signal and this systematic review focuses on one step: 'Do maternal factors influence the concentration of milk hormones?'

Objective

To systematically review human studies which analyze the association between maternal factors and the concentration of hormones in breast milk.

Methods

Three databases were searched for studies reporting the association of maternal factors including body mass index (BMI), weight, fat mass, age, ethnicity, smoking with hormones such as adiponectin, leptin, insulin, ghrelin, and cortisol in breast milk.

Results

Thirty-three studies were eligible for inclusion. Maternal BMI was positively associated with milk leptin (20/21 studies) and with milk insulin (4/6 studies). Maternal weight also displayed a positive correlation with milk leptin levels, and maternal diabetes status was positively associated with milk insulin concentrations. Conversely, evidence for associations between maternal fat mass, smoking, ethnicity and other maternal factors and hormone levels in breast milk was inconclusive or lacking.

Conclusion

Current evidence is consistent with a signaling role for leptin and insulin in breast milk, however other steps need to be investigated to understand the role of these components as definitive signals. This review represents a first step in establishing the role of signaling components in human milk and highlights other issues that need to be considered going forward.

Maternal Overweight and Obesity and Their Effect on the Growth of the Newborn During the First Six Months of Life

INTRODUCTION

 Maternal overweight and obesity during pregnancy have been shown to have multiple negative effects on the mother's health, which can even affect the infant's growth by increasing weight gain and altering various indicators, such as weight for age, length for age and weight for length. While breast milk on the other hand reduces these risks, and it's the best and most complete food for the newborn. It's a dynamic fluid capable of being modified to meet the needs of each stage of the newborn, but despite this capacity and the fact that maternal body mass index can have an impact on its components, through complex biological mechanisms, it manages to reduce the negative effects accumulated during pregnancy and even promotes a healthy state in the baby. In a country like Mexico, where overweight and obesity affect a large part of the population, it is important to study their causes and which could be the effect of this increased maternal overweight during pregnancy and lactation on newborns.

OBJECTIVE

Identify the alterations associated with increased maternal body mass index during pregnancy and breastfeeding on mothers' health and their possible effect on the growth of the newborn during the first six months of life.

MATERIAL AND METHODS

This was a prospective cohort study. Forty-two healthy binomials (mother and child), without problems during delivery and without serious illnesses during the breastfeeding period, were included. Maternal body mass index at the beginning of pregnancy allowed us to create two comparison groups between mothers: one with adequate weight, another with overweight or obesity. Follow-up was carried out once a month during the first six months of life, evaluating the somatometric development of mothers and children. All mothers completed the six-month period of exclusive breastfeeding.

RESULTS

 There were differences between both groups of women. The one that included overweight and obese women compared to the group of women with adequate weight had a higher number of pregnancies, abortions, plasma glucose levels in the third trimester of pregnancy, and a lower number of prenatal control visits and plasma platelet levels (all with p<0.05). Regarding the baby's growth, there was a difference between the weight for length classification at 60-, 120-, 150- and 180-day follow-ups. The group to which the mother was assigned with respect to her body mass index at the beginning of pregnancy (adequate weight group and overweight/obese group) was the only factor associated with the risk of the baby being overweight according to weight for length indicator at the 180-day follow-up, with an OR = 5.2 (95%CI 1.02-26.59).

CONCLUSIONS

Maternal overweight and obesity during pregnancy have a negative effect on the mother's health and baby's weight gain in its weight-for-length classification during the first six months of life. Although breastfeeding has been shown to have a positive effect on the growth of the baby, exposure to a higher maternal body mass index during pregnancy triggers important metabolic alterations that promote the development of diseases. It is important to establish weight control guidelines in women who wish to become pregnant to reduce the negative effects on the mother and offspring.

Relationship Between Maternal Age and Macronutrient Content of Colostrum

BACKGROUND

Little is known about the relationship between maternal age and the macronutrient content of colostrum.

RESEARCH AIMS

This study aimed to evaluate the relationship between maternal age and human milk macronutrient content by comparing the concentrations of lactose, proteins, and lipids in the colostrum of women with younger, moderate, and advanced maternal age.

METHODS

An observational, cross-sectional study was designed to compare the macronutrient concentrations in the colostrum of women aged < 20 years, 20 to 34 years, and > 34 years (younger, moderate, and advanced maternal age, respectively; n = 33 per group). For each participant, 3 ml of colostrum was collected by manual extraction from the right breast at 10 am, 39-48 hr after delivery, and analyzed using a Miris Human Milk Analyzer. Macronutrient concentrations were compared between the groups using analysis of variance. P < 0.05 was considered significant.

RESULTS

Mothers with moderate maternal age had a higher colostrum lipid concentration than those with younger or advanced maternal age (2.3 mg, SD = 1.4 mg vs. 1.5 mg, SD = 1.0 mg vs. 1.6 mg, SD = 0.9 mg, respectively; p = 0.007). Lactose and protein contents in the analyzed samples did not differ among the three study groups.

CONCLUSION

This study lends support to the potential variation of lipids in colostrum by maternal age and suggests individual adaptation to the nutritional components of milk to the needs of the infant may be beneficial.

Association of Human Milk Fatty Acid Composition with Maternal Cardiometabolic Diseases: An Exploratory Prospective Cohort Study

Background: Human milk fatty acids derive from maternal diet, body stores, and mammary synthesis and may reflect women's underlying cardiometabolic health. We explored whether human milk fatty acid composition was associated with maternal cardiometabolic disease (CMD) during pregnancy and up to 5 years postpartum. Materials and Methods: We analyzed data from the prospective CHILD Cohort Study on 1,018 women with no preexisting CMD who provided breast milk samples at 3-4 months postpartum. Milk fatty acid composition was measured using gas-liquid chromatography. Maternal CMD (diabetes or hypertension) was classified using questionnaires and birth records as no CMD (reference outcome group; 81.1%), perinatal CMD (developed and resolved during the perinatal period; 14.9%), persistent CMD (developed during, and persisted beyond, the perinatal period; 2.9%), and incident CMD (developed after the perinatal period; 1.1%). Multinomial logistic regression was used to model associations between milk fatty acid composition (individual, summary, ratios, and patterns identified using principal component analysis) and maternal CMD, adjusting for pre-pregnancy anthropometry and race/ethnicity. Results: Medium-chain saturated fatty acids (MC-SFA), lauric (C12:0; odds ratio [OR] = 0.73, 95% confidence interval [CI] = 0.60-0.89) and myristic acid (C14:0; OR = 0.80, 95% CI = 0.66-0.97), and the high MC-SFA principal component pattern (OR = 0.86, 95% CI = 0.76-0.96) were inversely associated with perinatal CMD. Long-chain polyunsaturated fatty acids adrenic acid (C22:4n-6) was positively associated with perinatal (OR = 1.21, 95% CI = 1.01-1.44) and persistent CMD (OR = 1.56, 95% CI = 1.08-2.25). The arachidonic (C20:4n-6)-to-docosahexaenoic acid (C22:6n-3) ratio was inversely associated with incident CMD (OR = 0.52, 95% CI = 0.28-0.96). Conclusions: These exploratory findings highlight a potential novel utility of breast milk for understanding women's cardiometabolic health.

Impact of polyunsaturated fatty acids during and pregnancy and lactation: A comprehensive review

BACKGROUND

Docosahexaenoic acid (DHA) and arachidonic acid (ARA) are relevant polyunsaturated fatty acids (PUFA) derived from alpha-linolenic acid (ALA) and linoleic acid (LA), respectively. These are important in pregnancy and lactation periods because of their benefits to the developing fetus and infant. Currently, the high prevalence of gestational obesity has led to a revision of PUFAs recommendations in these periods, due to changes in the lipid profile of women marked by a higher consumption of n-6 PUFA.

OBJECTIVE

This review aims to present an updated compilation of evidence on DHA and ARA during gestation and lactation.

METHODS

The literature review was performed in different databases, PubMed, Scopus, Web of Science, Scielo, ISI, and Ovid MedLine, highlighting the importance of DHA and ARA for newborn development.

RESULTS

An adequate intake of n-3 PUFA, especially DHA, in the mother during pregnancy and the postnatal period is important for the normal development of the child's brain. Maternal DHA supplementation increases DHA levels in mothers, but its direct link to infant neurodevelopment remains unclear. Obesity generates changes in the FA profile of pregnant women, causing an imbalance of n-3 and n-6 PUFA. An adequate level of DHA benefits children's cognitive function. However, a potential connection exists to the infants' inflammatory profile.

CONCLUSION

During gestation and lactation periods, an adequate DHA intake and n-6/ n-3 PUFA ratio (especially for obese women) are important for the optimal growth and brain development of the child.

Optimizing ARA and DHA in infant formula: A systematic review of global trends, regional disparities, and considerations for precision nutrition

In the context of precision nutrition, the addition of ARA and DHA in infant formula needs to consider more factors. This study conducted a comprehensive literature review, including 112 relevant Chinese and English articles, to summarize and analyze the global levels of ARA, DHA, and the ARA/DHA ratio in breast milk. The data were correlated with local aquatic products intake and children's IQ. The results indicated that the average level of DHA in breast milk across regions is lower than that of ARA. Variations in DHA content were identified as a primary factor influencing ARA/DHA ratio fluctuations. Breast milk ARA and DHA levels decrease with prolonged lactation periods but increase over the past 22 years. Correlation analysis revealed a significant positive relationship between aquatic products intake and breast milk DHA levels (r = 0.64, p < 0.05). Breast milk DHA levels also showed a significant positive correlation with children's IQ (r = 0.67, p < 0.01). Stable breast milk ARA content did not exhibit significant correlations with aquatic products intake or children's IQ (r = 0, p > 0.05). Among 22 infant formula products available in China, only 5 had ARA levels within the range of breast milk. Most formula products had higher ARA levels than DHA, resulting in ARA/DHA ratios generally exceeding 1. The temporal and spatial variability in breast milk ARA and DHA levels may lead to diverse health outcomes in infants. Therefore, the addition of ARA and DHA in infant formula should consider this variability, including the molecular forms and positional isomerism of the added ARA and DHA. Additionally, considering the impact of different cognitive development tests and infant's gene expression on formula assessment results, there is a need to establish a more comprehensive infant health assessment system to guide the addition of ARA and DHA in formula.

Postnatal Consumption of Black Bean Powder Protects against Obesity and Dyslipidemia in Male Adult Rat Offspring from Obese Pregnancies

The adverse influence of maternal obesity on offspring metabolic health throughout the life-course is a significant public health challenge with few effective interventions. We examined if black bean powder (BBP) supplementation to a high-calorie maternal pregnancy diet or a postnatal offspring diet could offer protection against the metabolic programming of metabolic disease risk in adult offspring. Female Sprague Dawley rats were randomly assigned to one of three diets (n = 10/group) for a 3-week pre-pregnancy period and throughout gestation and lactation: (i) a low-caloric control diet (CON); (ii) a high-caloric obesity-inducing diet (HC); or (iii) the HC diet with 20% black bean powder (HC-BBP). At weaning [postnatal day (PND) 21], one male pup from each dam was weaned onto the CON diet throughout the postnatal period until adulthood (PND120). In addition, a second male from the HC group only was weaned onto the CON diet supplemented with BBP (CON-BBP). Thus, based on the maternal diet exposure and offspring postnatal diet, four experimental adult offspring groups were compared: CON/CON, HC/CON, HC-BPP/CON, and HC/CON-BBP. On PND120, blood was collected for biochemical analysis (e.g., lipids, glycemic control endpoints, etc.), and livers were excised for lipid analysis (triglycerides [TG] and cholesterol) and the mRNA/protein expression of lipid-regulatory targets. Compared with the CON/CON group, adult offspring from the HC/CON group exhibited a higher (p < 0.05) body weight (BW) (682.88 ± 10.67 vs. 628.02 ± 16.61 g) and hepatic TG (29.55 ± 1.31 vs. 22.86 ± 1.85 mmol/g). Although maternal BBP supplementation (HC-BBP/CON) had little influence on metabolic outcomes, the consumption of BBP in the postnatal period (HC/CON-BBP) lowered hepatic TG and cholesterol compared with the other treatment groups. Reduced hepatic TG in the HC/CON-BBP was likely associated with lower postnatal BW gain (vs. HC/CON), lower mRNA and protein expression of hepatic Fasn (vs. HC/CON), and lower serum leptin concentration (vs. CON/CON and HC groups). Our results suggest that the postnatal consumption of a black-bean-powder-supplemented diet may protect male rat offspring against the programming of obesity and dyslipidemia associated with maternal obesity. Future work should investigate the bioactive fraction of BBP responsible for the observed effect.

Sampling Procedures for Estimating the Infant Intake of Human Milk Leptin, Adiponectin, Insulin, Glucose, and Total Lipid

Limited attention is given to the efficacy of protocols for the estimation of infant intake of milk components when investigating their impact on infant outcomes. We compared the actual measured intake of human milk components with estimations derived from 15 protocols to determine the most reliable approach for estimating intake of HM leptin, adiponectin, insulin, glucose, and total lipid. Twenty mothers who were 3-5 months postpartum completed a 24 h milk profile study with pre-/post-feed milk samples collection. The true infant intake (control group) based on 24 h milk intake (MI) was compared to estimated infant intakes using concentrations from five sampling protocols that were multiplied by one of true infant MI, considered mean MI (800 mL), or global mean MI (766 mL). The mean measured concentrations of six samples (three sets of pre- and post-feed samples, from morning (06:00-09:00), afternoon (13:00-16:00), and evening (19:00-22:00)) multiplied by the true infant MI, mean considered MI, and global mean MI produced the most accurate estimates of infant intake of these components. Therefore, in the absence of 24 h measurements and sampling, a sampling protocol comprising three sets of pre-/post-feed samples provides the most reliable infant intake estimates of HM leptin, adiponectin, insulin, glucose, and total lipid.

The association between human milk fatty acid composition in mothers with an elevated body mass index and infant growth changes

BACKGROUND & AIMS

Few studies have investigated alternations in human milk polyunsaturated fatty acid (PUFA) composition in the context of maternal obesity and its effects on infant growth trajectories. This study explored whether maternal weight status and breastfeeding type influence human milk FA composition and infant anthropometry during the first six months of life.

METHODS

Mother-infant dyads were enrolled from the Prediction of Allergies in Taiwanese Children birth cohort study. Data concerning maternal pre-pregnancy weight, infants' breastfeeding practices, and anthropometric data were obtained regularly. We identified and compared between the composition of 30 FAs in the colostrum and 2-month milk, respectively, in obese/overweight (OB/OW) and normal-weight (NW) mothers. Multiple linear regression analyses were performed to determine the association between PUFA composition at different lactation stages and infant anthropometric parameter changes and to identify the independent variables for body mass index (BMI) z-scores by six months of age.

RESULTS

We included 338 mother-infant dyads (OB/OW mothers, 16.9 %). OB/OW mothers exhibited lower total n-3 PUFAs (P = 0.035), higher ratios of arachidonic acid (C20:4n-6)/eicosapentaenoic acid (C20:5n-3) + docosahexaenoic acid (C22:6n-3), and n-6/n-3 PUFA in colostrum (P = 0.037 and 0.011, respectively), and their offspring had higher body weight and BMI z-scores. Nevertheless, no PUFA composition or n-6/n-3 PUFA ratios in colostrum and 2-month milk were associated with anthropometric parameter changes by age 6 months. Infant birth weight z-scores were independently associated with BMI outcomes at age 6 months (adjusted β = 0.16, 95 % confidence interval (0.05-0.35), P = 0.010) CONCLUSION: Neither n-3 nor n-6 PUFA profiles nor n-6/n-3 PUFA ratios at different lactation stages were found to be associated with anthropometric changes by age 6 months, suggesting that human milk PUFA composition may not be an important determinant of early infant growth trajectories.

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.

Human milk polyunsaturated fatty acids are related to neurodevelopmental, anthropometric, and allergic outcomes in early life: a systematic review

Polyunsaturated fatty acids are critically important for newborn nutrition and in the trajectory of growth and developmental processes throughout early life. This systematic review (PROSPERO ID: CRD42023400059) critically analyzes literature pertaining to how omega-3 and omega-6 fatty acids in human milk are related to health outcomes in early life. Literature selected for the review were published between 2005 and 2020 and included assessments in healthy term children between 0 and 5 years of age. The studies reported the relation between human milk fatty acids docosahexaenoic acid (C22:6n-3, DHA), eicosapentaenoic acid (C20:5n-3, EPA), alpha-linolenic acid (C18:3n-3, ALA), arachidonic acid (C20:4n-6, AA), and linoleic acid (C18:2n-6, LA) with three domains of health outcomes: neurodevelopment, body composition, and allergy, skin & eczema. Results from the 21 studies consistently suggested better health outcomes across the three domains for infants consuming milk with higher concentrations of total n-3, DHA, EPA, and ALA. Negative health outcomes across the three domains were associated with higher levels of total n-6, AA, and LA in milk. N-3 and n-6 content of milk were related to neurodevelopmental, body composition, and allergy, skin & eczema outcomes with moderate certainty. Maternal diet impacting milk fatty acid content and fatty acid desaturase genotype modifying physiologic responses to fatty acid intake were prominent gaps identified in the review using the NIH Quality Assessment Tool for Observational Cohort and Cross-Sectional Studies and GRADE approach. This research study can inform baby nutrition product development, and fatty acid intake recommendations or dietary interventions for mothers and children.

Leptin receptor expression in blood mononuclear cells of lactating women is associated with infant body weight: Potential role as a molecular biomarker

BACKGROUND

Molecular biomarkers of maternal leptin resistance associated with infant weight are needed.

OBJECTIVES

To evaluate gene expression of leptin receptor (LEPR), suppressor of cytokine signalling 3 (SOCS3) and insulin receptor in peripheral blood mononuclear cells (PBMCs) of lactating women and their relationship with infant body weight and adiposity.

METHODS

At day 10 postpartum, maternal gene expression in PBMCs as well as leptin and insulin concentrations in plasma and milk were assessed (n = 68). Infant weight and BMI z-scores, skinfolds and arm circumference were obtained at 10 days and/or at 3 months old.

RESULTS

In mothers with pre-pregnancy overweight or obesity (OW/OB), LEPR expression was reduced (p = 0.013) whereas plasma and milk leptin and milk insulin concentrations were elevated. LEPR expression was positively related with infant weight z-score (Beta (95% CI): 0.40 (0.17, 0.63), p = 0.001) but not with leptin concentrations. SOCS3 expression was positively related with infant weight z-score (Beta (95% CI): 0.28 (0.04, 0.51), p = 0.024) and arm circumference (Beta (95% CI): 0.57 (0.32, 0.82), p < 0.001). Relationships remained significant after adjusting for maternal and infant confounders.

CONCLUSIONS

LEPR and SOCS3 gene expression in PBMCs are novel maternal molecular biomarkers that reflect leptin resistance and are associated with infant body weight and adiposity.

Does human milk composition predict later risk of obesity? A systematic review

BACKGROUND

Possible mechanisms behind the association of breastfeeding with a lower risk of later obesity are unknown but one possibility is the unique composition of human milk. Here, we systematically reviewed the evidence linking breast-milk macronutrient and hormonal composition with later obesity.

METHODS

We searched 7 databases for studies that included infants predominantly breast-fed for the first 3 months and which analysed associations between a measure of breast-milk composition and later (> 6 months) measures of obesity or body composition.

RESULTS

47 publications were identified for full-text screening, of which 10 were eligible and only 3 found significant associations. Higher leptin concentration in breast milk at age 1 month was associated with lower infant BMI at 12, 18 and 24 months of age (1 study). Higher breast-milk adiponectin concentration at 6 weeks and 4 months were associated with adiposity at age 12 and 24 months (1 study). In 1 study, breast-milk carbohydrate content was positively associated, and fat content negatively associated, with adiposity at age 12 months. No significant associations were found between other hormones or macronutrients in human milk and later risk of obesity or body composition.

CONCLUSIONS

The evidence linking breast-milk composition with later obesity was inconsistent and confined to single, individual studies. Our review highlights the methodological limitations of previous studies and the need for further research in this area.

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.

A longitudinal study of fatty acid profiles, macronutrient levels, and plasmin activity in human milk

Introduction

Human milk provides nutrients essential for infant growth and health, levels of which are dynamic during lactation.

Methods

In this study, changes in macronutrients, fatty acids, and plasmin activities over the first six months of lactation in term milk were studied.

Results

There was a significant influence of lactation stage on levels of protein and plasmin activities, but not on levels of fat and carbohydrate in term milk. Concerning fatty acids in term milk, levels of caproic acid and α-linolenic acid increased significantly (p < 0.05), whereas those of arachidonic acid and docosahexaenoic acid decreased, in the six months after birth. Significant impacts of maternal pre-pregnancy BMI and infant gender on fatty acid profiles were also found. Multivariate statistical analysis showed that protein level, plasmin activity, and several fatty acids (α-linolenic acid, lignoceric acid, and docasadienoic acid) contributed strongly to discrimination of milk from different lactational stages.

Discussion

The study demonstrates that not all but some fatty acids were influenced by lactation, whereas protein and protease levels showed clear decreasing trends during lactation, which may help in understanding the nutritional requirements of infants.

Mechanisms of Maternal Diet-Induced Obesity Affecting the Offspring Brain and Development of Affective Disorders

Depression and metabolic disease are common disorders that share a bidirectional relationship and continue to increase in prevalence. Maternal diet and maternal behaviour both profoundly influence the developmental trajectory of offspring during the perinatal period. At an epidemiological level, both maternal depression and obesity during pregnancy have been shown to increase the risk of neuropsychiatric disease in the subsequent generation. Considerable progress has been made to understand the mechanisms by which maternal obesity disrupts the developing offspring gut-brain axis, priming offspring for the development of affective disorders. This review outlines such mechanisms in detail, including altered maternal care, the maternal microbiome, inflammation, breast milk composition, and maternal and placental metabolites. Subsequently, offspring may be prone to developing gut-brain interaction disorders with concomitant changes to brain energy metabolism, neurotransmission, and behaviour, alongside gut dysbiosis. The gut microbiome may act as a key modifiable, and therefore treatable, feature of the relationship between maternal obesity and the offspring brain function. Further studies examining the relationship between maternal nutrition, the maternal microbiome and metabolites, and offspring neurodevelopment are warranted to identify novel therapeutic targets.

Sex-specificities in offspring neurodevelopment and behaviour upon maternal glycation: Putative underlying neurometabolic and synaptic changes

AIM

Lactation is an important programming window for metabolic disease and neuronal alterations later in life. We aimed to study the effect of maternal glycation during lactation on offspring neurodevelopment and behaviour, assessing possible sex differences and underpinning molecular players.

METHODS

Female Wistar rats were treated with the Glyoxalase-1 inhibitor S-p-Bromobenzylguthione cyclopentyl diester (BBGC 5 mg/kg). A control and vehicle group treated with dimethyl sulfoxide were considered. Male and female offspring were tested at infancy for neurodevelopment hallmarks. After weaning, triglycerides and total antioxidant capacity were measured in breast milk. At adolescence, offspring were tested for locomotor ability, anxious-like behaviour, and recognition memory. Metabolic parameters were assessed, and the hippocampus and prefrontal cortex were collected for molecular analysis.

KEY FINDINGS

Maternal glycation reduced triglycerides and total antioxidant capacity levels in breast milk. At infancy, both male and female offspring presented an anticipation on the achievement of neurodevelopmental milestones. At adolescence, male offspring exposed to maternal glycation presented hyperlocomotion, whereas offspring of both sexes presented a risk-taking phenotype, accompanied by GABA_A receptor upregulation in the hippocampus. Females also demonstrated GABA_A and PSD-95 changes in prefrontal cortex. Furthermore, lower levels of GLO1 and consequently higher accumulation of AGES were also observed in both male and female offspring hippocampus.

SIGNIFICANCE

Early exposure to maternal glycation induces changes in milk composition leading to neurodevelopment changes at infancy, and sex-specific behavioural and neurometabolic changes at adolescence, further evidencing that lactation period is a critical metabolic programming window and in sculpting behaviour.

Influence of Maternal Metabolic Status and Diet during the Perinatal Period on the Metabolic Programming by Leptin Ingested during the Suckling Period in Rats

We aimed to analyze the long-term metabolic effects of leptin supplementation at physiological doses during suckling in the offspring of diet-induced obese rats, together with the potential benefits of improving maternal diet during lactation. Thus, the offspring of: dams fed standard-diet (SD) (CON-dams), dams fed western-diet (WD) before and during gestation and lactation (WD-dams), and dams fed as WD-dams but moved to SD during lactation (REV-dams) were supplemented throughout suckling with leptin or vehicle, and fed SD or WD from weaning to four months. Under SD, leptin treatment significantly improved metabolic profile and body fat accumulation, with stronger effects in the male offspring of CON-dams and REV-dams. Under WD, the offspring of WD-dams presented metabolic alterations that were not evident in the offspring of REV-dams. Moreover, leptin supplementation improved glucose homeostasis in the male offspring of REV-dams. Conversely, leptin supplementation in females born to WD-dams and fed WD from weaning resulted in impaired insulin sensitivity and increased hepatic lipid content. These results highlight the importance of a balanced maternal diet during the perinatal period, especially lactation, for the subsequent metabolic health of the offspring and for the beneficial effects of leptin supplementation during suckling, more evident in the male offspring.

Non-nutritive bioactive components in maternal milk and offspring development: a scoping review

Lactation is a critical time in mammalian development, where maternal factors shape offspring outcomes. In this scoping review, we discuss current literature concerning maternal factors that influence lactation biology and highlight important associations between changes in milk composition and offspring outcomes. Specifically, we explore maternal nutritional, psychosocial, and environmental exposures that influence non-nutritive bioactive components in milk and their links to offspring growth, development, metabolic, and behavioral outcomes. A comprehensive literature search was conducted using the Preferred Reporting Items for Systematic Reviews and Meta-Analysis Extension for Scoping Reviews (PRISMA-ScR) guidelines. Predetermined eligibility criteria were used to analyze 3,275 papers, and the final review included 40 primary research articles. Outcomes of this review identify maternal obesity to be a leading maternal factor influencing the non-nutritive bioactive composition of milk with notable links to offspring outcomes. Offspring growth and development are the most common modes of programming associated with changes in non-nutritive milk composition due to maternal factors in early life. In addition to discussing studies investigating these key associations, we also identify knowledge gaps in the current literature and suggest opportunities and considerations for future studies.

Influence of Maternal Body Fat on Levels of Insulin, Insulin-Like Growth Factor-1, and Obestatin

BACKGROUND

Insulin, insulin-like Growth Factor-1 (IGF-1), and obestatin in human milk originate from the circulation. There is also limited knowledge about the influence of body fat on the levels of these hormones in human milk.

RESEARCH AIM

To determine (1) the influence of body fat on levels of insulin, IGF-1, and obestatin in human milk and serum/plasma during the postpartum period; (2) the changes in the levels of these hormones in human milk and serum/plasma postpartum; and (3) the presence of IGF-1 mRNA in human milk.

METHODS

In this prospective, longitudinal, observational cohort study, levels of insulin, IGF-1, and obestatin were measured up to 30 days postpartum in milk and serum/plasma of 58 participants with adequate (≤ 32%) or excess (> 32%) total body fat determined by electrical bioimpedance. Student's t test and repeated-measures analysis of variance were used to evaluate the differences between groups. Pearson's test was used to analyze the associations.

RESULTS

The milk from participants with excess body fat had higher insulin and IGF-1 levels and lower obestatin levels than that of participants with adequate body fat at 3-7, 14-15, and 30 days postpartum (adjusted p < .001). The levels of insulin, IGF-1, and obestatin were significantly higher in human milk than in serum/plasma (p < .05) and correlated with maternal body fat (p < .001).

CONCLUSIONS

Maternal body fat was associated with elevated insulin and IGF-1 levels and decreased obestatin levels in human milk up to 30 days postpartum.

Breastmilk PUFA strongly associated with maternal dietary intake but not anthropometric parameters and breastmilk carotenoids

BACKGROUND

Long chain polyunsaturated fatty acids (PUFA) and the optimal n-6/n-3 fatty acids ratio are essential for proper neurodevelopment in infancy. This study aimed to evaluate the association between breastmilk fatty acid intake and maternal dietary intake, anthropometrics and breastmilk carotenoid levels.

METHODS

This observational, prospective study included 44 women in the first, third, and sixth month of lactation. At each study visit, maternal anthropometric measures were assessed and breastmilk samples were collected and assessed for fatty acids and carotenoids. At the third and sixth month, maternal diet was evaluated by three-day foods record.

RESULTS

Mean breastmilk docosahexaenoic (DHA) was 0.58%, 0.47%, and 0.49%, respectively at the 1, 3, and 6 month (p ≤ 0.05). Mean DHA intake were higher in month 3 compared to 6: 357 vs. 169 mg/day. Pre-pregnancy BMI was associated with SFA, PUFA, and n-6 PUFA at 1 month, whereas current BMI to SFA at months 1 and 3. DHA was correlated with lycopene, total carotenoids at 1 month and total carotenoids at month 3, whereas n-3 PUFA to lycopene at 1 month. DHA, n-3 PUFA, n-6 PUFA and saturated (SFA) levels were associated with its dietary intake both at months 3 and 6, AA/DHA and LA/ALA ratios only at month 3.

CONCLUSIONS

Maternal intake of PUFA and n-6/n-3 ratios were a good predictor of its breastmilk composition, whereas pre-pregnancy and current BMI, as well as breastmilk carotenoids had a limited influence.

Relationship between pre-pregnancy maternal body mass index and infant weight trajectories in HIV-exposed and HIV-unexposed infants

BACKGROUND

Maternal HIV and antiretroviral therapy (ART) exposure in utero may influence infant weight, but the contribution of maternal y body mass index (BMI) to early life overweight and obesity is not clear.

OBJECTIVE

To estimate associations between maternal BMI at entry to antenatal care (ANC) and infant weight through approximately 1 year of age and to evaluate whether associations were modified by maternal HIV status, maternal HIV and viral load, breastfeeding intensity through 6 months or timing of entry into ANC.

METHODS

We followed HIV-uninfected and -infected pregnant women initiating efavirenz-based ART from first antenatal visit through 12 months postpartum. Infant weight was assessed via World Health Organization BMI and weight-for-length z-scores (WLZ) at 6 weeks, 3, 6, 9 and 12 months. We used multivariable linear mixed-effects models to estimate associations between maternal BMI and infant z-scores over time.

RESULTS

In 861 HIV-uninfected infants (454 HIV-exposed; 407 HIV-unexposed), nearly 20% of infants were overweight or obese by 12 months of age, regardless of HIV exposure status. In multivariable analyses, increasing maternal BMI category was positively associated with higher infant BMIZ and WLZ scores between 6 weeks and 12 months of age and did not differ by HIV exposure status. However, HIV-exposed infants had slightly lower BMIZ and WLZ trajectories through 12 months of age, compared with HIV-unexposed infants across all maternal BMI categories. Differences in BMIZ and WLZ scores by HIV exposure were not explained by timing of entry into ANC or maternal viral load pre-ART initiation, but z-scores were slightly higher for HIV-exposed infants who were predominantly or exclusively versus partially breastfed.

CONCLUSIONS

These findings suggest maternal BMI influences early infant weight gain, regardless of infant HIV exposure status. Intervention to reduce maternal BMI may help to address growing concerns about obesity among HIV-uninfected children.

Association of Prepregnancy Obesity and Remodeled Maternal-Fetal Plasma Fatty Acid Profiles

Background

Fatty acids, especially polyunsaturated fatty acid (PUFA), are found abundantly in the brain and are fundamental for a fetus's growth. The fatty acid profiles of mothers and fetuses may be affected by maternal prepregnancy body mass index (pre-BMI), thus affecting fetal growth and development.

Methods

A total of 103 mother-fetus pairs were divided into overweight/obese (OW, n = 26), normal weight (NW, n = 60), and underweight (UW, n = 17) groups according to pre-BMI. Fatty acid profiles in maternal and umbilical cord plasma were analyzed by gas chromatography.

Results

The infant birth BMI z-score of the OW group was higher than that of the NW and UW groups (p < 0.05). The OW mothers had significantly higher plasma n-6 PUFA and n-6/n-3, but lower docosahexaenoic acid (DHA) and n-3 PUFA (p < 0.05). In cord plasma, the proportions of DHA and n-3 PUFA were lower in the OW group (p < 0.05), whereas the n-6/n-3 ratio was higher in the OW group (p < 0.05). The pre-BMI was negatively correlated with cord plasma DHA in all subjects (r = −0.303, p = 0.002), and the same negative correlation can be observed in the OW group (r = −0.561, p = 0.004), but not in the NW and UW groups (p > 0.05). The pre-BMI was positively correlated with cord plasma n-6/n-3 in all subjects (r = 0.325, p = 0.001), and the same positive correlation can be found in the OW group (r = 0.558, p = 0.004), but not in NW and UW groups (p > 0.05).

Conclusions

Maternal pre-BMI was associated with the maternal-fetal plasma fatty acid profiles, whereas the adverse fatty acid profiles are more noticeable in the prepregnancy OW mothers.

Adherence to Mediterranean Diet of Breastfeeding Mothers and Fatty Acids Composition of Their Human Milk: Results From the Italian MEDIDIET Study

Background and Aims

The content of fatty acids (FA) in human milk may be influenced by maternal nutrition. We evaluated the role of a Mediterranean diet in influencing the content of FA in human milk among 282 breastfeeding mothers participating in the MEDIDIET study.

Materials and Methods

Mediterranean Diet Score (MDS), a composite index, was used to evaluate adherence to the Mediterranean diet. It includes 9 components (i.e., vegetables, fruit, cereals, legumes, monounsaturated to saturated FA ratio – MUFA/SFA, fish, dairy products, meat, and alcohol) and therefore potentially ranges from 0 (no adherence) to 9 (complete adherence) points. None of the mothers obtained the highest score due to the low alcohol consumption in the study population. Mothers were categorized in approximate tertiles of adherence: 0–3 (34.4%), 4 (26.2%), and 5–8 points (39.4%). The mean content of FA across categories of MDS was compared using ANOVA and test for trend.

Results

A high adherence of breastfeeding mothers to the Mediterranean diet was associated with lower content of SFA in human milk (42.58 ± 4.36 for MDS = 0–3, 42.58 ± 4.89 for MDS = 4, and 40.92 ± 5.22% of fats for MDS = 5–8 points; p ANOVA and p for trend = 0.02). Conversely, a high adherence was associated with higher content of MUFA in human milk (43.27 ± 4.27 for MDS = 0–3, 43.27 ± 4.47 for MDS = 4, and 45.24 ± 5.22% of fats for MDS = 5–8 points; p ANOVA and p for trend &lt; 0.01), ω-3 FA (1.07 ± 0.25 for MDS = 0–3, 1.22 ± 0.49 for MDS = 4, and 1.31 ± 0.51% of fats for MDS = 5–8 points; p ANOVA and p for trend &lt; 0.01), and the major types of ω-3 FA (i.e., α-linolenic acid – ALA, eicosapentaenoic acid – EPA, docosahexaenoic acid – DHA, docosapentaenoic acid – DPA). These associations were mainly driven by the adherence to the vegetables, MUFA/SFA, fish, and dairy products components of the Mediterranean diet.

Conclusion

A high adherence to the Mediterranean diet was associated with human milk showing a lower content of SFA and higher content of MUFA and ω-3 FA, including DHA. The Mediterranean diet may contribute in human milk production with higher content of specific FA which is directly involved in infant’s neural and visual development, as reported by previous studies.

Short Term Changes in Dietary Fat Content and Metformin Treatment During Lactation Impact Milk Composition and Mammary Gland Morphology

Maternal health and diet can have important consequences for offspring nutrition and metabolic health. During lactation, signals are communicated from the mother to the infant through milk via macronutrients, hormones, and bioactive molecules. In this study we designed experiments to probe the mother-milk-infant triad in the condition of normal maternal health and upon exposure to high fat diet (HFD) with or without concurrent metformin exposure. We examined maternal characteristics, milk composition and offspring metabolic parameters on postnatal day 16, prior to offspring weaning. We found that lactational HFD increased maternal adipose tissue weight, mammary gland adipocyte size, and altered milk lipid composition causing a higher amount of omega-6 (n6) long chain fatty acids and lower omega-3 (n3). Offspring of HFD dams were heavier with more body fat during suckling. Metformin (Met) exposure decreased maternal blood glucose and several milk amino acids. Offspring of met dams were smaller during suckling. Gene expression in the lactating mammary glands was impacted to a greater extent by metformin than HFD, but both metformin and HFD altered genes related to muscle contraction, indicating that these genes may be more susceptible to lactational stressors. Our study demonstrates the impact of common maternal exposures during lactation on milk composition, mammary gland function and offspring growth with metformin having little capacity to rescue the offspring from the effects of a maternal HFD during lactation.

Insulin Concentration in Human Milk in the First Ten Days Postpartum: Course and Associated Factors

BACKGROUND OBJECTIVES

Human milk (HM) is better tolerated than formula in preterm infants. Insulin, which is naturally present in HM but not in formula, has been suggested as a key factor for feeding tolerance, as it appears to stimulate intestinal maturation. Its precise concentrations during the early postnatal period, however, remains unknown. The objective of this study was to assess the natural timecourse of the HM insulin concentration during the first ten days postpartum. The effect of preterm delivery, maternal obesity, and diurnal rhythm were also assessed.

METHOD

HM was collected from 31 non-diabetic mothers (21 preterm [gestational age (GA) < 37 weeks]; 10 at-term [GA ≥ 37 weeks]) on ≥ 4 time-points per day during the first five days, and once on the tenth day postpartum.

RESULTS

The HM insulin concentration declined rapidly within the first three days postpartum (day 1: 516 [312-1058] pmol/L; day 3: 157 [87-299] pmol/L), after which the concentration remained relatively stable. The insulin concentrations were higher in HM from obese mothers than from non-obese mothers (P < 0.001). Preterm delivery did not significantly affect HM insulin concentrations when adjusted for maternal pre-pregnancy body mass index category (P = 0.270). Diurnal rhythm was characterized by an insulin concentration decline throughout the night (P = 0.001), followed by an increase in the morning (P = 0.001).

CONCLUSION

The HM insulin concentration declines rapidly in the first three days postpartum, follows a diurnal rhythm, and is higher in obese mothers compared to non-obese mothers. HM insulin concentrations are not affected by preterm delivery.

Human Milk Metabolic Hormones: Analytical Methods and Current Understanding

Human milk (HM) contains a wide array of peptide hormones including leptin and adiponectin, which are involved in the regulation of infant growth and development. These essential hormones might play an important role in the regulation of metabolic reprogramming of the new-born infant. However, HM hormone studies are sparse and heterogeneous in regard to the study design, sample collection, preparation and analysis methods. This review discussed the limitations of HM hormone analysis highlighting the gaps in pre-analytical and analytical stages. The methods used to quantify HM metabolic hormones (leptin, adiponectin, ghrelin, insulin, obestatin, resistin and apelin) can be classified as immunoassay, immunosensor and chromatography. Immunoassay methods (ELISA and RIA) have been predominantly used in the measurement of these HM hormones. The relative validity parameters of HM hormones analysis are often overlooked in publications, despite the complexity and differences of HM matrix when compared to that of plasma and urine. Therefore, appropriate reports of validation parameters of methodology and instrumentation are crucial for accurate measurements and therefore better understanding of the HM metabolic hormones and their influences on infant outcomes.

Mismatch between obesogenic intrauterine environment and low-fat postnatal diet may confer offspring metabolic advantage

OBJECTIVE

Mismatch between a depleted intrauterine environment and a substrate-rich postnatal environment confers an increased risk of offspring obesity and metabolic syndrome. Maternal diet-induced obesity (MATOB) is associated with the same outcomes. These experiments tested the hypothesis that a mismatch between a nutrient-rich intrauterine environment and a low-fat postnatal environment would ameliorate offspring metabolic morbidity.

METHODS

C57BL6/J female mice were fed either a 60% high-fat diet (HFD) or a 10% fat control diet (CD) for 14-week pre-breeding and during pregnancy/lactation. Offspring were weaned to CD. Weight was evaluated weekly; body composition was determined using EchoMRI. Serum fasting lipids and glucose and insulin tolerance tests were performed. Metabolic rate, locomotor, and sleep behavior were evaluated with indirect calorimetry.

RESULTS

MATOB-exposed/CD-weaned offspring of both sexes had improved glucose tolerance and insulin sensitivity compared to controls. Males had improved fasting lipids. Females had significantly increased weight and body fat percentage in adulthood compared to sex-matched controls. Females also had significantly increased sleep duration and reduced locomotor activity compared to males.

CONCLUSIONS

Reduced-fat dietary switch following intrauterine and lactational exposure to MATOB was associated with improved glucose handling and lipid profiles in adult offspring, more pronounced in males. A mismatch between a high-fat prenatal and low-fat postnatal environment may confer a metabolic advantage. The amelioration of deleterious metabolic programming by strict offspring adherence to a low-fat diet may have translational potential.

Maternal Obesity: A Focus on Maternal Interventions to Improve Health of Offspring

Maternal obesity has many implications for offspring health that persist throughout their lifespan that include obesity and cardiovascular complications. Several different factors contribute to obesity and they encompass interplay between genetics and environment. In the prenatal period, untreated obesity establishes a foundation for a myriad of symptoms and negative delivery experiences, including gestational hypertensive disorders, gestational diabetes, macrosomia, and labor complications. However, data across human and animal studies show promise that nutritional interventions and physical activity may rescue much of the adverse effects of obesity on offspring metabolic health. Further, these maternal interventions improve the health of the offspring by reducing weight gain, cardiovascular disorders, and improving glucose tolerance. Mechanisms from animal studies have also been proposed to elucidate the signaling pathways that regulate inflammation, lipid metabolism, and oxidative capacity of the tissue, ultimately providing potential specific courses of treatment. This review aims to pinpoint the risks of maternal obesity and provide plausible intervention strategies. We delve into recent research involving both animal and human studies with maternal interventions. With the increasing concerning of obesity rates witnessed in the United States, it is imperative to acknowledge the long-term effects posed on future generations and specifically modify maternal nutrition and care to mitigate these adverse outcomes.

Perspective: Moving Toward Desirable Linoleic Acid Content in Infant Formula

Infant formula should provide the appropriate nutrients and adequate energy to facilitate healthy infant growth and development. If conclusive data on quantitative nutrient requirements are not available, the composition of human milk (HM) can provide some initial guidance on the infant formula composition. This paper provides a narrative review of the current knowledge, unresolved questions, and future research needs in the area of HM fatty acid (FA) composition, with a particular focus on exploring appropriate intake levels of the essential FA linoleic acid (LA) in infant formula. The paper highlights a clear gap in clinical evidence as to the impact of LA levels in HM or formula on infant outcomes, such as growth, development, and long-term health. The available preclinical information suggests potential disadvantages of high LA intake in the early postnatal period. We recommend performing well-designed clinical intervention trials to create clarity on optimal levels of LA to achieve positive impacts on both short-term growth and development and long-term functional health outcomes.

The clinical impact of maternal weight on offspring health: lights and shadows in breast milk metabolome

INTRODUCTION

Pre-pregnancy overweight and obesity, depending on maternal nutrition and metabolic state, can influence fetal, neonatal and long-term offspring health, regarding cardio-metabolic, respiratory, immunological and cognitive outcomes. Thus, maternal weight can act, through mechanisms that are not full understood, on the physiology and metabolism of some fetal organs and tissues, to adapt themselves to the intrauterine environment and nutritional reserves. These effects could occur by modulating gene expression, neonatal microbiome, and through breastfeeding.

AREAS COVERED

In this paper, we investigated the potential effects of metabolites found altered in breast milk (BM) of overweight/obese mothers, through an extensive review of metabolomics studies, and the potential short- and long-term clinical effects in the offspring, especially regarding overweight, glucose homeostasis, insulin resistance, oxidative stress, infections, immune processes, and neurodevelopment.

EXPERT OPINION

Metabolomics seems the ideal tool to investigate BM variation depending on maternal or fetal/neonatal factors. In particular, BM metabolome alterations according to maternal conditions were recently pointed out in cases of gestational diabetes, preeclampsia, intrauterine growth restriction and maternal overweight/obesity. In our opinion, even if BM is the food of choice in neonatal nutrition, the deepest comprehension of its composition in overweight/obese mothers could allow targeted supplementation, to improve offspring health and metabolic homeostasis.

The Triad Mother-Breast Milk-Infant as Predictor of Future Health: A Narrative Review

The benefits of human milk for both mother and infant are widely acknowledged. Human milk could represent a link between maternal and offspring health. The triad mother-breast milk-infant is an interconnected system in which maternal diet and lifestyle might have effects on infant's health outcome. This link could be in part explained by epigenetics, even if the underlining mechanisms have not been fully clarified yet. The aim of this paper is to update the association between maternal diet and human milk, pointing out how maternal diet and lifestyle could be associated with breast-milk composition, hence with offspring's health outcome.

Obesogenic Programming Effects during Lactation: A Narrative Review and Conceptual Model Focusing on Underlying Mechanisms and Promising Future Research Avenues

Animal studies have consistently demonstrated that maternal obesity and a high-fat diet during lactation enhances obesity risk in the offspring. However, less is known about these potential obesogenic programming effects in obese humans. We propose three important pathways that may explain obesogenic programming effects of human breastmilk. First, human milk components and hormones may directly affect child eating and satiety characteristics. Second, human milk constituents can affect child microbiota that, in turn, may influence child eating and weight outcomes. Third, human milk composition may affect child eating and weight outcomes through flavor exposure. We reviewed a few very recent findings from well-powered longitudinal or experimental human research with regard to these three pathways. Moreover, we provide a research agenda for future intervention research with the overarching aim to prevent excessive pediatric weight gain during lactation and beyond. The ideas presented in this paper may represent important “black box” constructs that explain obesogenic programming effects during lactation. It should be noted, however, that given the scarcity of studies, findings should be seen as working hypotheses to further test in future research.

Obese mother offspring have hepatic lipidic modulation that contributes to sex-dependent metabolic adaptation later in life

With the increasing prevalence of obesity in women of reproductive age, there is an urgent need to understand the metabolic impact on the fetus. Sex-related susceptibility to liver diseases has been demonstrated but the underlying mechanism remains unclear. Here we report that maternal obesity impacts lipid metabolism differently in female and male offspring. Males, but not females, gained more weight and had impaired insulin sensitivity when born from obese mothers compared to control. Although lipid mass was similar in the livers of female and male offspring, sex-specific modifications in the composition of fatty acids, triglycerides and phospholipids was observed. These overall changes could be linked to sex-specific regulation of genes controlling metabolic pathways. Our findings revised the current assumption that sex-dependent susceptibility to metabolic disorders is caused by sex-specific postnatal regulation and instead we provide molecular evidence supporting in utero metabolic adaptations in the offspring of obese mothers.