Human Milk Exposure Research Articles

Childhood Nutritional Factors and Cardiometabolic Outcomes at 9–11 y of Age: Findings from the ROLO Longitudinal Birth Cohort Study

BackgroundChildhood represents a critical period of nutritional risk in the programming of later chronic disease. Few longitudinal studies have explored repeated measures of nutrition throughout the first decade of life in relation to preteen cardiometabolic outcomes. ObjectivesThis research aimed to explore associations of early feeding practices (human milk exposure and duration and timing of introduction to solids) and childhood dietary quality and inflammatory scores (at 5 and 9–11 y and change during childhood) on preteen cardiometabolic outcomes. MethodsThis is an analysis of children from the ROLO longitudinal birth cohort study (n = 399). Information on early feeding practices were obtained at postnatal study visits. Food frequency questionnaires collected maternal-reported dietary intakes for each child at 5 and 9–11 y of age. Healthy Eating Index (HEI)-2015 and the Children’s Dietary Inflammatory Index (C-DII) scores were calculated. Anthropometry, body composition, blood pressure, heart rate, cardiorespiratory endurance, and blood biomarkers were obtained at 9–11 y. Crude and adjusted linear regression models examined nutritional exposure associations with preteen cardiometabolic outcomes. ResultsIn the adjusted model, any human milk exposure was associated with lower body fat (%) at 9–11 y (β: −2.86; 95% confidence interval [CI]: −5.46, −0.27; P = 0.03), than never receiving human milk. At 5 y, diet scores were favorably associated with lean mass at 9–11 y (P < 0.05 for both). Higher preteen HEI-2015 scores were associated with lower preteen leptin levels (tertile 3 compared with tertile 1—β: −2.92; 95% CI: −5.64, −0.21; P = 0.03). Diet quality significantly deteriorated (HEI-2015 score decreased) and became more proinflammatory (C-DII score increased) from 5 to 9–11 y of age. Diet quality/inflammation deterioration (compared with improvement) or overall change in dietary scores were not related to preteen cardiometabolic outcomes. ConclusionsExposure to human milk in early life was associated with lower preteen adiposity, irrespective of duration. Diet quality/inflammatory potential deteriorated between early childhood and the preteen years, highlighting a potential period for intervention.

Role of breastfeeding in disease prevention.

Human milk provides the infant with many bioactive factors, including immunomodulating components, antimicrobials and prebiotics, which modulate the infant microbiome and immune system maturation. As a result, breastfeeding can impact infant health from infancy, through adolescence, and into adulthood. From protecting the infant from infections, to reducing the risk of obesity, type 1 diabetes and childhood leukaemia, many positive health outcomes are observed in infants receiving breastmilk. For the mother, breastfeeding protects against postpartum bleeding and depression, increases weight loss, and long-term lowers the risk of type 2 diabetes, breast and ovarian cancer, and cardiovascular diseases. Beyond infants and mothers, the wider society is also impacted because of avoidable costs relating to morbidity and mortality derived from a lack of human milk exposure. In this review, Medline was used to search for relevant articles to discuss the health benefits of breastfeeding and its societal impact before exploring future recommendations to enhance our understanding of the mechanisms behind breastfeeding's positive effects and promote breastfeeding on a global scale.

Maternal Pre-Pregnancy BMI, Breastfeeding, and Child BMI.

Breastfeeding practices may protect against offspring obesity, but this relationship is understudied among women with obesity. We describe the associations between breastfeeding practices and child BMI for age z-score (BMIz), stratified by maternal BMI. We analyzed 8134 dyads from 21 cohorts in the Environmental Influences on Child Health Outcomes Program. Dyads with data for maternal pre-pregnancy BMI, infant feeding practices, and ≥1 child BMI assessment between the ages of 2 and 6 years were included. The associations between breastfeeding practices and continuous child BMIz were assessed by using multivariable linear mixed models. Maternal pre-pregnancy BMI category prevalence was underweight: 2.5%, healthy weight: 45.8%, overweight: 26.0%, and obese: 25.6%. Median child ages at the cessation of any breastfeeding and exclusive breastfeeding across the 4 BMI categories were 19, 26, 24, and 17 weeks and 12, 20, 17, and 12 weeks, respectively. Results were in the hypothesized directions for BMI categories. Three months of any breastfeeding was associated with a lower BMIz among children whose mothers were a healthy weight (-0.02 [-0.04 to 0.001], P = .06), overweight (-0.04 [-0.07 to -0.004], P = .03), or obese (-0.04 [-0.07 to -0.006], P = .02). Three months of exclusive breastfeeding was associated with a lower BMIz among children whose mothers were a healthy weight (-0.06 [-0.10 to -0.02], P = .002), overweight (-0.05 [-0.10 to 0.005], P = .07), or obese (-0.08 [-0.12 to -0.03], P = .001). Human milk exposure, regardless of maternal BMI category, was associated with a lower child BMIz in the Environmental Influences on Child Health Outcomes cohorts, supporting breastfeeding recommendations as a potential strategy for decreasing the risk of offspring obesity.

A Review of the Relationship Between the Appetite-Regulating Hormone Leptin Present in Human Milk and Infant Growth.

Objective: The relationship between leptin in human milk (HM) and infant growth is quite controversial. The aim of the present study was to review the epidemiological literature currently available on the relation between the appetite-regulating hormone leptin in HM with growth and infant weight gain. Also, to know if it influences on the center of satiety of the infant, and if this hormone has an effect in the self-regulation of food intake. Methods: A review of review and original research articles published from January 1, 2015 up to December 31, 2019 measuring leptin in HM and infant weight gain was performed in the PubMed and Embase databases. The literature showed a total of 237 articles, where the title and abstract were evaluated to eliminate duplicate citations and later exclusion criteria were established to discard articles. Eighteen articles met the inclusion criteria. Results: Six articles showed a relationship between leptin present in HM and infant weight. Five articles reported on leptin in HM and the effect on satiety and self-regulation of infant intake. Studies of leptin in infant serum blood were quite controversial. There is an inverse relationship between the leptin in HM and infant weight gain. Also, breastfed infants better self-regulate their intake and have a better relationship with food. The duration of breastfeeding directly influences on the growth of the infant due to the hormones present in the milk. However, these mechanisms are unclear, and the results are controversial. Conclusion: The evidence from the studies allowed us to establish that there is an association between leptin in HM and infant weight gain. However, there is still a lack of longitudinal studies, with a larger number of participants and well-established inclusion criteria about the relationship between leptin in HM exposure and the development of infant weight gain.

Fecal Bacterial Communities Differ by Lactation Status in Postpartum Women and Their Infants.

Previous research examined effects of human milk on the infant gut microbiota, but little attention has been given to the microbiota of lactating women. To determine associations between exclusive human milk feeding and gut microbiota characteristics in mothers and infants at 6-weeks postpartum. A sample of mother-infant dyads (N = 24) provided fecal samples and questionnaire responses at 6-weeks postpartum as part of the Pregnancy, EAting & POstpartum Diapers study. Deoxyribonucleic acid was extracted from stool samples, followed by (V4) 16S ribosomal ribonucleic acid gene amplicon sequencing. Alpha and beta diversity, in addition to taxa differences, were compared by human milk exposure status, exclusive versus non-exclusive. A subset of dyads (those exclusively fed human milk; n = 14) was analyzed for shared bifidobacterial species using polymerase chain reaction. Alpha diversity was significantly lower in exclusively human milk-fed infants. Maternal lactation status (exclusive vs. partial) and Shannon diversity were associated in univariate analysis but were no longer associated in multivariable regression including body mass index category in the model. Beta diversity (Sorensen dissimilarity) of fecal samples from women and infants was significantly associated with human milk feeding. Of six infants with Bifidobacterium longum subspecies longum in their fecal samples, all their mothers shared the same species. Maternal gut microbiotas differ by lactation status, a relationship potentially confounded by body mass index category. Further research is needed to identify whether lactation directly influences the maternal gut microbiota, which may be another mechanism by which lactation influences health.

The Abundance of Human Milk Oligosaccharide (HMO)-Metabolizing Genes in Fecal Samples from Six-Month-Old Human Infants.

Herein, we report the abundance and prevalence of HMO-metabolizing genes, specifically those of Bifidobacterium infantis, in fecal samples from human infants. Forty dyads were enrolled, and each mother collected a fecal sample from her infant at six months of age. Genomic DNA was extracted, and quantitative real-time PCR was used to determine gene abundance. The mode of delivery was not associated with gene abundance. Several gene regions, Sia (a sialidase), B. inf (16S), and GH750 (a glycoside hydrolase), were more abundant in the feces of human milk-fed infants (p < 0.05). Others, Sia and HC bin (16S), tended to be less abundant when a larger percentage of an infant’s diet consisted of solids (p < 0.10). When accounting for solid food intake, human milk exposure was positively associated with Sia and B. inf (p < 0.05) and tended to be related to the abundance of the GH750 and HC bin (p < 0.10) gene regions. With further development and validation in additional populations of infants, these assays could be used to group samples by dietary exposure even where no record of dietary intake exists. Thus, these assays would provide a method by which infant human milk intake can be assessed quickly in any well-equipped molecular biology laboratory.

Human Milk Oligosaccharide (HMO) Metabolizing Gene Abundances in Human Infant Fecal Samples

ObjectivesTo benefit from the complex oligosaccharides found in human milk, an infant relies on microbial metabolism of these compounds. The main objective of this study was to determine the abundance of Bifidobacterium infantis human milk oligosaccharide (HMO) metabolizing genes in infant fecal samples. MethodsFecal samples from 40 6-mos-old infants were collected. Genomic DNA was extracted, and quantitative real-time PCR was used to determine the abundance of several genes in B. infantis. B infantis specific primer sets were used to target 5 HMO metabolizing genes as well as the 16S rRNA gene. Additional 16S rRNA primer sets were used to target overall bacteria, overall Bifidobacterium, B. breve and B. longum. Abundances of each qPCR reaction were compared by infant human milk exposure, solid food intake, and mode of delivery. ResultsMode of delivery was not associated with any PCR targets. Two HMO genes, a sialidase and a glycoside hydrolase, as well as a B. infantis 16S rRNA gene were more abundant in the feces of human milk fed infants (p < 0.05). The sialidase and a B. infantis 16S rRNA gene tended to be less abundant when a larger percentage of an infant’s diet consisted of solids (p < 0.10). When accounting for solid food intake, human milk exposure continued to be positively associated with the sialidase and a B. infantis 16S rRNA gene abundance (p < 0.05) and tended to be related to the abundance of the glycoside hydrolase (p < 0.10). An assessment of 5 B. infantis specific primer sets targeting HMO metabolizing genes demonstrated that the stools of human milk fed infants harbored a more diverse set of these genes than those of non-human milk fed infants (p = 0.02). ConclusionsHerein, we have identified a qPCR primer set targeting a sialidase that is consistently associated with human milk exposure even in the presence of solid food intake. With further development and validation in additional populations of infants, these assays could be used to group samples by dietary exposure even where no record of dietary intake exists. Thus, this assay would provide a method by which infant human milk intake proximal to sample collection can be assessed quickly in any well-equipped molecular biology lab. Funding SourcesThis research was partially supported by the MSU College of Agriculture and Natural Resources Undergraduate Research Program as well as the Max Gonzenbach Research Scholarship.

The infant gut microbiota at 12 months of age is associated with human milk exposure but not with maternal pre-pregnancy body mass index or infant BMI-for-age z-scores.

BackgroundAs obesity rates continue to rise, it is increasingly important to understand factors that can influence body weight and growth, especially from an early age. The infant gut microbiota has broad effects on a variety of bodily processes, but its relation to infant growth is not yet fully characterized. Since the infant gut microbiota is closely related to breastfeeding practices and maternal health, understanding the relationship between these factors and infant growth may provide insight into the origins of childhood obesity.ObjectivesIdentify the relationship between human milk exposure, maternal pre-pregnancy body mass index (BMI), the infant gut microbiota, and 12-month-old BMI-for-age z-scores (12M BAZ) to identify key factors that shape infant growth.MethodsTwo Michigan cohorts (ARCHGUT and BABYGUT) comprised of a total of 33 mother-infant dyads provided infant fecal samples at 12M. After DNA extraction, amplification, and sequencing of the V4 16S rRNA region using Illumina MiSeq v2 Chemistry, gut bacterial diversity metrics were analyzed in relation to human milk exposure, maternal pre-pregnancy BMI, and infant growth parameters.ResultsRecent human milk exposure was inversely related to maternal pre-pregnancy BMI and most strongly associated with infant gut bacterial community membership and individual gut microbiota richness differences. Maternal pre-pregnancy BMI was not associated with the infant gut microbiota after adjusting for human milk exposure. However, maternal pre-pregnancy BMI was the only factor significantly associated with 12M BAZ.ConclusionsHuman milk exposure is one of the central influences on the infant gut microbiota at 12M of age. However, the lack of association between the infant gut microbiota and 12M-old infant BAZ suggests that genetic, physiological, dietary, and other environmental factors may play a more direct role than the gut microbiota in determining infant BAZ at 12M.

Estimating Length of Stay for Simple Gastroschisis

BackgroundLength of stay (LOS) is an important measure of quality; however, estimating LOS for rare populations such as gastroschisis is problematic. Our objective was to identify explanatory variables for LOS and build a model to estimate LOS in neonates with simple gastroschisis. MethodsIn 73 neonates with simple gastroschisis (47% female, 67% White), statistical correlations for 31 potential explanatory variables for LOS were evaluated using multivariate linear regression. Poisson regression was used to estimate LOS in predetermined subpopulations, and a life table model was developed to estimate LOS for simple gastroschisis. ResultsFemale sex (−2.4 d), “time to silo placement” (0.9 d), total parenteral nutrition days (0.6 d), need for any nasogastric feedings (11.4 d) and at discharge (−7 d), “feeding tolerance” (0.4 d), days to first postoperative stool (−0.3 d), and human milk exposure (−3.4 d) associated with LOS in simple gastroschisis. Estimated LOS for preterm neonates was longer than term infants (5.4 versus 4.6 wk) but similar for estimates based on sex and race. Based on these associations, we estimate that >50% of neonates with simple gastroschisis will be discharged by hospital day 35. ConclusionsWe identified several associations that explained variations in LOS and developed a novel model to estimate LOS in simple gastroschisis, which may be applied to other rare populations.

Human Milk Feeding Patterns at 6 Months of Age are a Major Determinant of Fecal Bacterial Diversity in Infants.

Maternal pre-pregnancy obesity and human milk feeding have been associated with altered infant gut microbiota. Determine the relationships between maternal pre-pregnancy BMI, human milk exposure, and their influence on the infant microbiota simultaneously. This was a cross-sectional study of infants at 6 months of age (N = 36), a time when many infants are fed a mixed diet of human milk and other foods. Fecal samples and participant information were collected from a subset of dyads enrolled in two related prospective cohorts (ARCHGUT and BABYGUT) in Michigan. Sequencing the V4 region of the 16S gene was used to analyze fecal bacterial samples collected from 6-month-old infants. Participants were grouped into four categories designated by their extent of human milk exposure (100%, 80%, 50%-80%, ≤ 20% human milk in the infant diet) and by maternal pre-pregnancy BMI category (normal, overweight, obese). Fewer participants with pre-pregnancy obesity were breastfeeding at 6 months postpartum compared to non-obese participants (35.7% and 81.8%, respectively). In univariate analyses, maternal pre-pregnancy BMI and human milk exposure were both significantly associated with alpha and beta diversity of the infant microbiota. However, in multivariate analyses, human milk exposure accounted for 20% of the variation in alpha diversity, but pre-pregnancy BMI was not significantly associated with any form of microbiota diversity. The proportion of the infant diet that was human milk at 6 months was the major determinant of alpha and beta diversity of the infant. Maternal obesity contributes to the gut microbiota by its association with the extent of human milk feeding.

The Infant Gut Microbiota at 12 Months and Its Associations with Maternal Pre-pregnancy BMI, Human Milk Exposure and Infant BMI-for-age Z-score (OR01-05-19)

ObjectivesDetermine if the infant gut microbiota at 12 months of age is associated with maternal pre-pregnancy BMI or infant human milk (HM) exposure. Additionally, determine whether infant BMI z-score at 12 months is associated with the infant microbiota composition and richness at 6 and 12 months. MethodsFecal samples were collected from infants at 6 (n = 35) and 12 (n = 32) months of age. Maternal pre-pregnancy BMI, infant weight and height, and the amount of HM in the infant diet were self-reported. Infant BMI for age z-scores (BAZ) were calculated using WHO Anthro software. Fecal communities were analyzed by 16S rRNA (V4) sequencing on an Illumina Miseq. ResultsInfants who had HM at 12 months had lower microbiota richness than infants who only received it until 6 months or were not exposed. Microbial community membership (Sorensen) was also significantly different in infants who received any HM at 12 months compared to infants who only received it until 6 months or were not exposed. The 12-month microbiota was similar for infants who received HM until 6 months or had no exposure. Infant BAZ at 12 months positively correlated with maternal pre-pregnancy BMI. Fewer infants born to obese women were exposed to HM at 12 months compared to those born to normal weight women. However, HM exposure at 12 months was not associated with infant BAZ at 12 months. In the 12-month microbiota, Shannon diversity also positively correlated with maternal pre-pregnancy BMI. No alpha or beta diversity metrics of the infant microbiota at 6 months were associated with infant BAZ at 12 months. However, the Shannon diversity of the 12-month microbiota tended to be positively associated the 12-month infant BAZ. ConclusionsMaternal pre-pregnancy BMI was associated with higher gut microbiota diversity at 12 months of age. This increase in diversity may influence host metabolism, providing a mechanistic link for elevated BAZ in infants whose mothers had an elevated BMI prior to becoming pregnant. Funding SourcesMichigan State AgBioResearch, Child Health Advances through Research with Mothers, Michigan Health Endowment Fund, and the NIH Environmental Influences on Child Health Outcomes (ECHO) Program (Prenatal Exposures and Child Health Outcomes: A Statewide Study (UG3 OD023285)).

The Effect of a Donor Milk Policy on the Diet of Very Low Birth Weight Infants.

Use of donor milk (DM) to supplement mother's own milk (MOM) in the neonatal intensive care unit (NICU) is steadily increasing based on health and developmental benefits to premature infants. A paucity of data exists documenting the effect of DM use on the diet of very low birth weight (VLBW) infants related to the implementation of a DM policy. This study aimed to compare VLBW enteral intake type in the first 28 days of life before versus after establishing a DM policy. This single-center pre-post prospective cohort study included all inborn infants ≤ 1500 grams in a level 4 NICU remaining hospitalized at 28 days and admitted either before (pre-DM period, October 2009-March 2010) or after (DM period, October 2010-September 2012) implementing a DM policy. The feeding protocol was unchanged in both periods. Collected data included maternal/infant demographics, infant clinical data, and daily volume of enteral intake as MOM, DM, and formula. The proportion of enteral feeds from these sources during the first 28 days of life was compared pre-DM versus DM. Compared to pre-DM baseline, formula exposure was significantly decreased, and human milk exposure and proportion of diet as human milk increased. The proportion of infants fed exclusively human milk increased. Exposure to and proportion of diet as MOM was unchanged. Infants were fed earlier in the DM period. Establishment of a DM policy was associated with reduced exposure to formula, promoting an exclusively human milk diet, with earlier initiation of feeds and no decrease in use of MOM.

Variation of maternal milk adiponectin and its correlation with infant growth

To investigate the variation of human breast milk adiponectin (APN) concentration during lactation, analyze the relationship of APN concentrations in human breast milk with APN in infant serum, determine the association between maternal milk APN and infant body proportionality in the first year of life, and the period of greatest human milk exposure. Subjects included 73 mother-infant pairs from Shanghai International Peace Maternity & Child Health Hospital. Maternal milk was collected at 2, 4, 13, 26 weeks and infant serum was collected at 26 weeks. The concentration of APN in maternal milk and infant serum were measured with commercially available ELISAs (R&D Systems). Weight-for-age Z-scores (WAZ), length-for-age Z-scores (LAZ), weight-for-length Z-scores (WLZ) and body mass index Z-scores (zBMI) of infants up to 1 year of age were calculated using World Health Organization (WHO) standards. Then the variation of maternal milk APN was investigated, the correlation between maternal milk APN and infant serum APN was analyzed; multivariate regression analysis was used to analyze covariates correlated with infant body proportionality, meanwhile determined the association between maternal milk APN and infant anthropometrics. The concentration of APN in maternal milk at 2, 4, 13, 26 weeks was respectively (14.62 µg/L, 5.93 - 140.40 µg/L), (7.32 µg/L, 2.04 - 29.35 µg/L), (6.84 µg/L, 2.72 - 15.65 µg/L) and (4.88 µg/L, 1.12 - 13.38 µg/L). Higher milk APN in postpartum 2 weeks was associated with lower infant WAZ at 13, 26 and 52 weeks (P < 0.05). Milk APN in postpartum 4 weeks was inversely related to infant WAZ, WLZ, zBMI at 13, 26 and 52 weeks (all P < 0.05). Meanwhile, milk APN in postpartum 13 weeks had significantly negative correlation with infant WAZ, WLZ, zBMI at 13, 26 and 52 weeks (P < 0.01). Milk APN in postpartum 26 weeks also was inversely associated with infant WAZ, WLZ and zBMI at 52 weeks (P < 0.05). After adjusting covariates like birth weight using multivariate regression analysis, milk APN level is the most important influence factor to infant WAZ, WLZ, zBMI at 13, 26 and 52 weeks. There was a positive correlation between maternal milk APN and infant serum APN at 13, 26 weeks. Milk APN concentration declines throughout lactation. Maternal milk APN may play a vital role in the growth and development of breastfed infants, particularly closely associated with infant weight. Infant serum APN clearly correlated with maternal milk APN.

Human Milk Exposure Blocks Calcium Influx Into Human Polymorphonuclear Leukocytes ♦ 24

Considering that human milk (HM) supresses multiple Ca++ -regulated human polymorphonuclear leukocyte (PMN) functions, we sought to examine the effects of HM on PMN Ca++ metabolism. Fura-2 loaded PMN were exposed to HM, infant formula (FOR) or Hanks Balanced Salt Solution + Ca++ (HBSS) for 10 sec - 30 min and re-suspended in HBSS ± Ca++. Cytosolic Ca++ concentration [CaF] was monitored ± 10-6M f MLP, ± 100nM thapsigargin, ± 1mM extracellular CaCl2. HM exposure did not alter peak [CaF] following f MLP exposure but lowered the subsequent [CaF] fMLP response based on area under the curve (nmol*min) [HBSS: 828±36(Mean±SE) nmol*min; FOR: 638±42 nmol*min; HM: 405±42 nmol*min, p<0.02 HM vs HBSS or FOR]. This effect was observed with HM exposures as brief as 10 sec, persisted for 4 hr after removal from HM, was concentration-dependent and was associated with secondary Ca++-stores depletion. HM-exposure did not affect [CaF] after fMLP when cells were re-suspended in a zero Ca++-buffer, but extracellular addition of 1mM CaCl2 significantly increased [CaF] in HBSS and FOR -exposed PMN, but not HM-treated PMN [HBSS: 437±35 nmol*min; FOR: 718±57 nmol*min; HM: 302±15 nmol*min, p<0.02 HM vs HBSS or FOR], suggesting that HM exposure resulted in blockade of Ca++ influx. HM also blocked spontaneous Mn++ uptake by PMN over 20 min, based on loss of fura-2 fluorescence (%) [HBSS: 39±4%; FOR: 31±4%; HM: 23±4%, p<0.05 HM vs HBSS or FOR]. These data show that HM exposure blocks Ca++ influx in PMN. We speculate that this effect potentially explains the anti-inflammatory properties of HM on PMN.