Associations between human milk oligosaccharides and infant body composition in the first 6 mo of life

Carbohydrates in Human Milk and Body Composition of Term Infants during the First 12 Months of Lactation

Human milk (HM) carbohydrates may affect infant appetite regulation, breastfeeding patterns, and body composition (BC). We investigated relationships between concentrations/calculated daily intakes (CDI) of HM carbohydrates in first year postpartum and maternal/term infant BC, as well as breastfeeding parameters. BC of dyads (n = 20) was determined at 2, 5, 9, and/or 12 months postpartum using ultrasound skinfolds (infants) and bioelectrical impedance spectroscopy (infants/mothers). Breastfeeding frequency, 24-h milk intake and total carbohydrates (TCH) and lactose were measured to calculate HM oligosaccharides (HMO) concentration and CDI of carbohydrates. Statistical analysis used linear regression/mixed effects models; results were adjusted for multiple comparisons. Higher TCH concentrations were associated with greater infant length, weight, fat-free mass (FFM), and FFM index (FFMI), and decreased fat mass (FM), FM index (FMI), %FM and FM/FFM ratio. Higher HMO concentrations were associated with greater infant FFM and FFMI, and decreased FMI, %FM, and FM/FFM ratio. Higher TCH CDI were associated with greater FM, FMI, %FM, and FM/FFM ratio, and decreased infant FFMI. Higher lactose CDI were associated with greater FM, FMI, %FM, and FM/FFM, ratio and decreased FFMI. Concentrations and intakes of HM carbohydrates differentially influence development of infant BC in the first 12 months postpartum, and may potentially influence risk of later obesity via modulation of BC.

Cow's Milk Allergy: Immunomodulation by Dietary Intervention

Cow’s milk proteins cause allergic symptoms in 2% to 3% of all infants. In these individuals, the physiological mechanism of tolerance is broken with subsequent possible sensitization to antigens, which can lead eventually to allergic responses. The present review aims to provide an overview of different aspects of immune modulation by dietary intervention in cow’s milk allergy (CMA). It focuses on pathogenetic mechanisms of different CMA related disorders, e.g., gastroesophageal reflux and eosinophilic esophagitis, highlighting the role of dietary management on innate and adaptive immune systems. The traditional dietary management of CMA has greatly changed in the last years, moving from a passive approach, consisting of an elimination diet to relieve symptoms, to a “proactive” one, meaning the possibility to actively modulate the immune system. Thus, new insights into the role of hydrolysates and baked milk in immunomodulation are addressed here. Additionally, nutritional components, such as pre- and probiotics, may target the immune system via microbiota, offering a possible road map for new CMA prevention and treatment strategies.

Maternal and Infant Factors Associated with Human Milk Oligosaccharides Concentrations According to Secretor and Lewis Phenotypes

Human milk oligosaccharides (HMOs) are multifunctional carbohydrates naturally present in human milk that act as prebiotics, prevent pathogen binding and infections, modulate the immune system and may support brain development in infants. HMOs composition is very individualized and differences in HMOs concentrations may affect the infant's health. HMOs variability can be partially explained by the activity of Secretor (Se) and Lewis (Le) genes in the mother, but non-genetic maternal factors may also be involved. In this cross-sectional, observational study, 78 single human milk samples ranging from 17 to 76 days postpartum (median: 32 days, IQR: 25-46 days) were collected from breastfeeding Brazilian women, analyzed for 16 representative HMOs by liquid chromatography coupled to mass spectrometry and associations between maternal and infant factors with HMOs concentrations were investigated. HMOs concentrations presented a high variability even in women with the same SeLe phenotype and associations with maternal allergic disease, time postpartum and with infant's weight, weight gain and sex. Overall, we present unprecedented data on HMOs concentrations from breastfeeding Brazilian women and novel associations of maternal allergic disease and infant's sex with HMOs concentrations. Differences in HMOs composition attributed to maternal SeLe phenotype do not impact infant growth, but higher concentrations of specific HMOs may protect against excessive weight gain.

The Function and Alteration of Immunological Properties in Human Milk of Obese Mothers

Maternal obesity is associated with metabolic changes in mothers and higher risk of obesity in the offspring. Obesity in breastfeeding mothers appears to influence human milk production as well as the quality of human milk. Maternal obesity is associated with alteration of immunological factors concentrations in the human milk, such as C-reactive protein (CRP), leptin, IL-6, insulin, TNF-Alpha, ghrelin, adiponectin, and obestatin. Human milk is considered a first choice for infant nutrition due to the complete profile of macro nutrients, micro nutrients, and immunological properties. It is essential to understand how maternal obesity influences immunological properties of human milk because alterations could impact the nutrition status and health of the infant. This review summarizes the literature regarding the impact of maternal obesity on the concentration of particular immunological properties in the human milk.

Comprehensive Preterm Breast Milk Metabotype Associated with Optimal Infant Early Growth Pattern

Early nutrition impacts preterm infant early growth rate and brain development but can have long lasting effects as well. Although human milk is the gold standard for feeding new born full-term and preterm infants, little is known about the effects of its bioactive compounds on breastfed preterm infants' growth outcomes. This study aims to determine whether breast milk metabolome, glycome, lipidome, and free-amino acids profiles analyzed by liquid chromatography-mass spectrometry had any impact on the early growth pattern of preterm infants. The study population consisted of the top tercile-Z score change in their weight between birth and hospital discharge ("faster grow", n = 11) and lowest tercile ("slower grow", n = 15) from a cohort of 138 premature infants (27⁻34 weeks gestation). This holistic approach combined with stringent clustering or classification statistical methods aims to discriminate groups of milks phenotype and identify specific metabolites associated with early growth of preterm infants. Their predictive reliability as biomarkers of infant growth was assessed using multiple linear regression and taking into account confounding clinical factors. Breast-milk associated with fast growth contained more branched-chain and insulino-trophic amino acid, lacto-N-fucopentaose, choline, and hydroxybutyrate, pointing to the critical role of energy utilization, protein synthesis, oxidative status, and gut epithelial cell maturity in prematurity.

Stunting, wasting and breast-feeding as correlates of body composition in Cambodian children at 6 and 15 months of age

The study aimed at assessing stunting, wasting and breast-feeding as correlates of body composition in Cambodian children. As part of a nutrition trial (ISRCTN19918531), fat mass (FM) and fat-free mass (FFM) were measured using2H dilution at 6 and 15 months of age. Of 419 infants enrolled, 98 % were breastfed, 15 % stunted and 4 % wasted at 6 months. At 15 months, 78 % were breastfed, 24 % stunted and 11 % wasted. Those not breastfed had lower FMI at 6 months but not at 15 months. Stunted children had lower FM at 6 months and lower FFM at 6 and 15 months compared with children with length-for-agez≥0. Stunting was not associated with height-adjusted indexes fat mass index (FMI) or fat-free mass index (FFMI). Wasted children had lower FM, FFM, FMI and FFMI at 6 and 15 months compared with children with weight-for-lengthz(WLZ) ≥0. Generally, FFM and FFMI deficits increased with age, whereas FM and FMI deficits decreased, reflecting interactions between age and WLZ. For example, the FFM deficits were –0·99 (95 % CI –1·26, –0·72) kg at 6 months and –1·44 (95 % CI –1·69; –1·19) kg at 15 months (interaction,P<0·05), while the FMI deficits were –2·12 (95 % CI –2·53, –1·72) kg/m2at 6 months and –1·32 (95 % CI –1·77, –0·87) kg/m2at 15 months (interaction,P<0·05). This indicates that undernourished children preserve body fat at the detriment of fat-free tissue, which may have long-term consequences for health and working capacity.

Association of Maternal Secretor Status and Human Milk Oligosaccharides With Milk Microbiota: An Observational Pilot Study

BACKGROUND AND OBJECTIVES

Breast milk contains several bioactive factors including human milk oligosaccharides (HMOs) and microbes that shape the infant gut microbiota. HMO profile is determined by secretor status; however, their influence on milk microbiota is still uncovered. This study is aimed to determine the impact of the FUT2 genotype on the milk microbiota during the first month of lactation and the association with HMO.

METHODS

Milk microbiota from 25 healthy lactating women was determined by quantitative polymerase chain reaction and 16S gene pyrosequencing. Secretor genotype was obtained by polymerase chain reaction-random fragment length polymorphisms and by HMO identification and quantification.

RESULTS

The most abundant bacteria were Staphylococcus and Streptococcus, followed by Enterobacteriaceae-related bacteria. The predominant HMO in secretor milk samples were 2'FL and lacto-N-fucopentaose I, whereas non-secretor milk was characterized by lacto-N-fucopentaose II and lacto-N-difucohexaose II. Differences in microbiota composition and quantity were found depending on secretor/non-secretor status. Lactobacillus spp, Enterococcus spp, and Streptococcus spp were lower in non-secretor than in secretor samples. Bifidobacterium genus and species were less prevalent in non-secretor samples. Despite no differences on diversity and richness, non-secretor samples had lower Actinobacteria and higher relative abundance of Enterobacteriaceae, Lactobacillaceae, and Staphylococcaceae.

CONCLUSIONS

Maternal secretor status is associated with the human milk microbiota composition and is maintained during the first 4 weeks. Specific associations between milk microbiota, HMO, and secretor status were observed, although the potential biological impact on the neonate remains elusive. Future studies are needed to reveal the early nutrition influence on the reduction of risk of disease.

Human Milk Oligosaccharide Concentrations Are Associated with Multiple Fixed and Modifiable Maternal Characteristics, Environmental Factors, and Feeding Practices

Background

Human milk oligosaccharides (HMOs) shape the developing gut microbiome and influence immune function. Aside from genetic Secretor status, the factors influencing HMO synthesis and secretion are largely unknown.

Objective

We aimed to identify modifiable and nonmodifiable factors associated with HMO concentrations.

Methods

This prospective observational study included a representative subset of 427 mothers participating in the CHILD birth cohort (mean age: 33 y, 73% Caucasian). Breast milk was collected at 3-4 mo postpartum. Concentrations of 19 predominant HMOs were measured by rapid high-throughput HPLC. Secretor status was defined by the presence of 2'-fucosylactose. Associations with maternal, infant, and environmental factors were explored using multivariable regression. Breastfeeding duration was explored as a secondary outcome.

Results

Overall, 72% of mothers were Secretors and the mean ± SD duration of any breastfeeding was 12.8 ± 5.7 mo. HMO profiles were highly variable; total HMO concentrations varied 3.7-fold and individual HMOs varied 20- to >100-fold. Secretor mothers had higher total HMO concentrations than did non-Secretors (mean: 15.91 ± 2.80 compared with 8.94 ± 1.51 μmol/mL, P < 0.001) and all individual HMOs differed by Secretor status, except for disialyllacto-N-tetraose (DSLNT). Most HMO concentrations were lower in milk collected later in lactation, although some were higher including DSLNT and 3'-sialyllactose. Independent of Secretor status and lactation stage, seasonal and geographic variation was observed for several HMOs. Parity, ethnicity, and breastfeeding exclusivity also emerged as independent factors associated with some HMOs, whereas diet quality and mode of delivery did not. Together, these factors explained between 14% (for 6'-sialyllactose) and 92% (for 2'-fucosyllactose) of the observed variation in HMO concentrations. Lower concentrations of lacto-N-hexaose or fucodisialyllacto-N-hexaose were associated with earlier breastfeeding cessation.

Conclusions

HMO concentrations vary widely between mothers and are associated with multiple characteristics beyond genetic Secretor status, as well as feeding practices and environmental factors. Further research is warranted to determine how these associations affect infant health. This study was registered at clinicaltrials.gov as NCT03225534.

The Human Microbiome and Child Growth - First 1000 Days and Beyond

The assembly of microbial communities within the gastrointestinal tract during early life plays a critical role in immune, endocrine, metabolic, and other host developmental pathways. Environmental insults during this period, such as food insecurity and infections, can disrupt this optimal microbial succession, which may contribute to lifelong and intergenerational deficits in growth and development. Here, we review the human microbiome in the first 1000 days - referring to the period from conception to 2 years of age - and using a developmental model, we examine the role of early microbial succession in growth and development. We propose that an 'undernourished' microbiome is intergenerational, thereby perpetuating growth impairments into successive generations. We also identify and discuss the intertwining host-microbe-environment interactions occurring prenatally and during early infancy, which may impair the trajectories of healthy growth and development, and explore their potential as novel microbial targets for intervention.

Excessive Weight Gain Followed by Catch-Down in Exclusively Breastfed Infants: An Exploratory Study

Some infants experience excessive weight gain (EWG) during exclusive breastfeeding, but causes and consequences are unknown. The objective was to identify factors associated with early EWG. Infants with EWG (HW-group) were examined at 5, 9 and 18 mo and compared to a breastfed group with normal weight gain (NW-group). Anthropometry, body composition, milk and blood samples, and milk intake were measured. Mean body-mass-index-for-age z-scores (BAZ) increased 1.93 from birth to 5 mo in the HW-group (n = 13) while the NW-group (n = 17) was unchanged (-0.01). The HW-group had 70% more fat mass at 5 mo, and then showed marked catch-down in BAZ from 5 to 18 mo (-0.84). Milk intake at 5⁻6 mo did not differ between the groups. In the HW-group milk-leptin was lower at 5 mo and serum-leptin was considerably higher at 5 and 9 mo compared to the NW-group. Serum-leptin at 5 mo was positively associated with weight-for-age z-score (WAZ) and fat mass and negatively with WAZ change from 5 to 9 mo. In conclusion, breastfed infants with EWG had catch-down growth when other foods were introduced. Low milk-leptin in the HW-group may have stimulated appetite and milk intake when weight gain was high. High serum-leptin in the HW-group suggests early leptin resistance, which could impact cerebral regulation of energy intake. Larger studies are needed to confirm these results.

Breastfeeding and growth during infancy among offspring of mothers with gestational diabetes mellitus: a prospective cohort study

BACKGROUND

Breastfeeding (BF) may protect against obesity and type 2 diabetes mellitus in children exposed to maternal diabetes in utero, but its effects on infant growth among this high-risk group have rarely been evaluated.

OBJECTIVES

The objective of this study was to evaluate BF intensity and duration in relation to infant growth from birth through 12 months among offspring of mothers with gestational diabetes mellitus (GDM).

METHODS

Prospective cohort of 464 GDM mother-infant dyads (28% White, 36% Hispanic, 26% Asian, 8% Black, 2% other). Weight and length measured at birth, 6-9 weeks, 6 months and 12 months. Categorized as intensive BF or formula feeding (FF) groups at 6-9 weeks (study baseline), and intensity from birth through 12 months as Group 1: consistent exclusive/mostly FF, Group 2: transition from BF to FF within 3-9 months and Group 3: consistent exclusive/mostly BF. Multivariable mixed linear regression models estimated adjusted mean (95% confidence interval) change in z-scores; weight-for-length (WLZ), weight-for-age and length-for-age.

RESULTS

Compared with intensive BF at 6-9 weeks, FF showed greater increases in WLZ-scores from 6 to 9 weeks to 6 months [+0.38 (0.13 to 0.62) vs. +0.02 (-0.15 to 0.19); p = 0.02] and birth to 12 months [+1.11 (0.87 to 1.34) vs. +0.53 (0.37 to 0.69); p < 0.001]. For 12-month intensity and duration, Groups 2 and 3 had smaller WLZ-score increases than Group 1 from 6 to 9 weeks to 6 months [-0.05 (-0.27 to 0.18) and +0.07 (-0.19 to 0.23) vs. +0.40 (0.15 to 0.64); p = 0.01 and 0.07], and birth to 12 months [+0.60 (0.39 to 0.82) and +0.59 (0.33 to 0.85) vs. +0.97 (0.75 to 1.19); p < 0.05].

CONCLUSIONS

Among offspring of mothers with GDM, high intensity BF from birth through 1 year is associated with slower infant ponderal growth and lower weight gain.

Linkage-Specific Detection and Metabolism of Human Milk Oligosaccharides in Escherichia coli

Human milk oligosaccharides (HMOs) are important prebiotic complex carbohydrates with demonstrated beneficial effects on the microbiota of neonates. However, optimization of their biotechnological synthesis is limited by the relatively low throughput of monosaccharide and linkage analysis. To enable high-throughput screening of HMO structures, we constructed a whole-cell biosensor that uses heterologous expression of glycosidases to generate linkage-specific, quantitative fluorescent readout for a range of HMOs at detection limits down to 20 μM in approximately 6 hr. We also demonstrate the use of this system for orthogonal control of growth rate or protein expression of particular strains in mixed populations. This work enables rapid non-chromatographic linkage analysis and lays the groundwork for the application of directed evolution to biosynthesis of complex carbohydrates as well as the prebiotic manipulation of population dynamics in natural and engineered microbial communities.

Human Milk Nutrient Composition in the United States: Current Knowledge, Challenges, and Research Needs

Human milk is considered to be the ideal food for infants. Accurate, representative, and up-to-date nutrient composition data of human milk are crucial for the management of infant feeding, assessment of infant and maternal nutritional needs, and as a guide for developing infant formula. Currently in the United States, the nutrient profiles of human milk can be found in the USDA National Nutrient Database for Standard Reference, and in books or review articles. Nonetheless, these resources all suffer major drawbacks, such as being outdated, incomplete profiles, limited sources of data, and uncertain data quality. Furthermore, no nutrient profile was developed specifically for the US population. The purposes of this review were to summarize the current knowledge of human milk nutrient composition from studies conducted in the United States and Canada, and to identify the knowledge gaps and research needs. The literature review was conducted to cover the years 1980-2017, and 28 research papers were found containing original data on macronutrients and micronutrients. Most of these 28 studies were published before 1990 and mainly examined samples from small groups of generally healthy lactating women. The experimental designs, including sampling, storage, and analytic methods, varied substantially between the different studies. Data of several components from these 28 studies showed some consistency for 1-6 mo postpartum, especially for protein, fat, lactose, energy, and certain minerals (e.g., calcium). The data for 7-12 mo postpartum and for other nutrients are very scarce. Comprehensive studies are required to provide current and complete nutrient information on human milk in the United States.

Human milk oligosaccharide composition predicts risk of necrotising enterocolitis in preterm infants

OBJECTIVE

Necrotising enterocolitis (NEC) is one of the most common and often fatal intestinal disorders in preterm infants. Markers to identify at-risk infants as well as therapies to prevent and treat NEC are limited and urgently needed. NEC incidence is significantly lower in breast-fed compared with formula-fed infants. Infant formula lacks human milk oligosaccharides (HMO), such as disialyllacto-N-tetraose (DSLNT), which prevents NEC in neonatal rats. However, it is unknown if DSLNT also protects human preterm infants.

DESIGN

We conducted a multicentre clinical cohort study and recruited 200 mothers and their very low birthweight infants that were predominantly human milk-fed. We analysed HMO composition in breast milk fed to infants over the first 28 days post partum, matched each NEC case with five controls and used logistic regression and generalised estimating equation to test the hypothesis that infants who develop NEC receive milk with less DSLNT than infants who do not develop NEC.

RESULTS

Eight infants in the cohort developed NEC (Bell stage 2 or 3). DSLNT concentrations were significantly lower in almost all milk samples in NEC cases compared with controls, and its abundance could identify NEC cases prior to onset. Aggregate assessment of DSLNT over multiple days enhanced the separation of NEC cases and control subjects.

CONCLUSIONS

DSLNT content in breast milk is a potential non-invasive marker to identify infants at risk of developing NEC, and screen high-risk donor milk. In addition, DSLNT could serve as a natural template to develop novel therapeutics against this devastating disorder.

Human milk composition and infant growth

PURPOSE OF REVIEW

This review highlights relevant studies published between 2015 and 2017 on human milk composition and the association with infant growth.

RECENT FINDINGS

High-quality studies investigating how human milk composition is related to infant growth are sparse. Recent observational studies show that human milk concentrations of protein, fat, and carbohydrate likely have important influence on infant growth and body composition. Furthermore, some observational studies examining human milk oligosaccharides and hormone concentrations suggest functional relevance to infant growth. For human milk micronutrient concentrations and microbiota content, and other bioactive components in human milk, the association with infant growth is still speculative and needs further investigation. The included studies in this review are all limited in their methodological design and methods but have interesting potential in understanding infant growth.

SUMMARY

Available evidence on human milk composition in relation to infant growth is sparse. This review summarizes recent publications investigating human milk composition; including micro- and macronutrients, human milk oligosaccharides, hormones and other bioactive components, and the association with infant weight, length, body mass index, and body composition.

Pharmacokinetics of Sucralose and Acesulfame-Potassium in Breast Milk Following Ingestion of Diet Soda

OBJECTIVE

The aim of this study was to determine sucralose and acesulfame-potassium (ace-K) pharmacokinetics in breast milk following maternal ingestion of a diet soda.

METHODS

Thirty-four exclusively breast-feeding women (14 normal-weight, 20 obese) consumed 12 ounces of Diet Rite Cola, sweetened with 68-mg sucralose and 41-mg ace-K, before a standardized breakfast meal. Habitual non-nutritional sweeteners intake was assessed via a diet questionnaire. Breast milk was collected from the same breast before beverage ingestion and hourly for 6 hours.

RESULTS

Owing to one mother having extremely high concentrations, peak sucralose and acesulfame-potassium concentrations following ingestion of diet soda ranged from 4.0 to 7387.9 ng/mL (median peak 8.1 ng/mL) and 299.0 to 4764.2 ng/mL (median peak 945.3 ng/mL), respectively.

CONCLUSIONS

Ace-K and sucralose transfer into breast milk following ingestion of a diet soda. Future research should measure concentrations after repeated exposure and determine whether chronic ingestion of sucralose and acesulfame-potassium via the breast milk has clinically relevant health consequences.

Gut microbiota alterations and dietary modulation in childhood malnutrition - The role of short chain fatty acids

The gut microbiome affects the health status of the host through different mechanisms and is associated with a wide variety of diseases. Both childhood undernutrition and obesity are linked to alterations in composition and functionality of the gut microbiome. One of the possible mechanisms underlying the interplay between microbiota and host metabolism is through appetite-regulating hormones (including leptin, ghrelin, glucagon-like peptide-1). Short chain fatty acids, the end product of bacterial fermentation of non-digestible carbohydrates, might be able to alter energy harvest and metabolism through enteroendocrine cell signaling, adipogenesis and insulin-like growth factor-1 production. Elucidating these mechanisms may lead to development of new modulation practices of the gut microbiota as a potential prevention and treatment strategy for childhood malnutrition. The present overview will briefly outline the gut microbiota development in the early life, gut microbiota alterations in childhood undernutrition and obesity, and whether this relationship is causal. Further we will discuss possible underlying mechanisms in relation to the gut-brain axis and short chain fatty acids, and the potential of probiotics, prebiotics and synbiotics for modulating the gut microbiota during childhood as a prevention and treatment strategy against undernutrition and obesity.

Phenotype diffusion and one health: A proposed framework for investigating the plurality of obesity epidemics across many species

We propose the idea of "phenotype diffusion," which is a rapid convergence of an observed trait in some human and animal populations. The words phenotype and diffusion both imply observations independent of mechanism as phenotypes are observed traits with multiple possible genetic mechanisms and diffusion is an observed state of being widely distributed. Recognizing shared changes in phenotype in multiple species does not by itself reveal a particular mechanism such as a shared exposure, shared adaptive need, particular stochastic process or a transmission pathway. Instead, identifying phenotype diffusion suggests the mechanism should be explored to help illuminate the ways human and animal health are connected and new opportunities for optimizing these links. Using the plurality of obesity epidemics across multiple species as a prototype for shared changes in phenotype, the goal of this review was to explore eco-evolutionary theories that could inform further investigation. First, evolutionary changes described by hologenome evolution, pawnobe evolution, transposable element (TE) thrust and the drifty gene hypothesis will be discussed within the context of the selection asymmetries among human and animal populations. Secondly, the ecology of common source exposures (bovine milk, xenohormesis and "obesogens"), niche evolution and the hygiene hypothesis will be summarized. Finally, we synthesize these considerations. For example, many agricultural breeds have been aggressively selected for weight gain, microbiota (e.g., adenovirus 36, toxoplasmosis) associated with (or infecting) these breeds cause experimental weight gain in other animals, and these same microbes are associated with human obesity. We propose applications of phenotype diffusion could include zoonotic biosurveillance, biocontainment, antibiotic stewardship and environmental priorities. The One Health field is focused on the connections between the health of humans, animals and the environment, and so identification of phenotype diffusion is highly relevant for practitioners (public health officials, physicians and veterinarians) in this field.

Effects of infant formula composition on long-term metabolic health

Early nutrition may have long-lasting metabolic impacts in adulthood. Even though breast milk is the gold standard, most infants are at least partly formula-fed. Despite obvious improvements, infant formulas remain perfectible to reduce the gap between breastfed and formula-fed infants. Improvements such as reducing the protein content, modulating the lipid matrix and adding prebiotics, probiotics and synbiotics, are discussed regarding metabolic health. Numerous questions remain to be answered on how impacting the infant formula composition may modulate the host metabolism and exert long-term benefits. Interactions between early nutrition (composition of human milk and infant formula) and the gut microbiota profile, as well as mechanisms connecting gut microbiota to metabolic health, are highlighted. Gut microbiota stands as a key actor in the nutritional programming but additional well-designed longitudinal human studies are needed.

Composition and Variation of Macronutrients, Immune Proteins, and Human Milk Oligosaccharides in Human Milk From Nonprofit and Commercial Milk Banks

BACKGROUND

When human milk is unavailable, banked milk is recommended for feeding premature infants. Milk banks use processes to eliminate pathogens; however, variability among methods exists. Research aim: The aim of this study was to compare the macronutrient (protein, carbohydrate, fat, energy), immune-protective protein, and human milk oligosaccharide (HMO) content of human milk from three independent milk banks that use pasteurization (Holder vs. vat techniques) or retort sterilization.

METHODS

Randomly acquired human milk samples from three different milk banks ( n = 3 from each bank) were analyzed for macronutrient concentrations using a Fourier transform mid-infrared spectroscopy human milk analyzer. The concentrations of IgA, IgM, IgG, lactoferrin, lysozyme, α-lactalbumin, α antitrypsin, casein, and HMO were analyzed by mass spectrometry.

RESULTS

The concentrations of protein and fat were significantly ( p < .05) less in the retort sterilized compared with the Holder and vat pasteurized samples, respectively. The concentrations of all immune-modulating proteins were significantly ( p < .05) less in the retort sterilized samples compared with vat and/or Holder pasteurized samples. The total HMO concentration and HMOs containing fucose, sialic acid, and nonfucosylated neutral sugars were significantly ( p < .05) less in retort sterilized compared with Holder pasteurized samples.

CONCLUSION

Random milk samples that had undergone retort sterilization had significantly less immune-protective proteins and total and specific HMOs compared with samples that had undergone Holder and vat pasteurization. These data suggest that further analysis of the effect of retort sterilization on human milk components is needed prior to widespread adoption of this process.

Systematic review of the concentrations of oligosaccharides in human milk

Context

Oligosaccharides are the third largest solid component in human milk. These diverse compounds are thought to have numerous beneficial functions in infants, including protection against infectious diseases. The structures of more than 100 oligosaccharides in human milk have been elucidated so far.

Objective

The aim of this review was to identify the main factors that affect the concentrations of oligosaccharides in human milk and to determine whether it is possible to calculate representative and reliable mean concentrations.

Data Sources

A comprehensive literature search on oligosaccharide concentrations in human milk was performed in 6 electronic databases: BIOSIS, Current Contents Search, Embase, Lancet Titles, MEDLINE and PubMed.

Study Selection

The initial search resulted in 1363 hits. After the elimination of duplicates, the literature was screened. The application of strict inclusion criteria resulted in 21 articles selected.

Data Extraction

Oligosaccharide concentrations, both mean values and single values, reported in the literature were sorted by gestational age, secretor status of mothers, and defined lactation periods.

Results

Mean concentrations, including confidence limits, of 33 neutral and acidic oligosaccharides reported could be calculated. Concentrations of oligosaccharides in human milk show variations that are dependent on both the secretor type of the mother and the lactation period as examined by analyses of variance. In addition, large interlaboratory variations in the data were observed.

Conclusions

Worldwide interlaboratory quantitative analyses of identical milk samples would be required to identify the most reliable methods of determining concentrations of oligosaccharides in human milk. The data presented here contribute to the current knowledge about the composition and quantities of oligosaccharides in human milk and may foster greater understanding of the biological functions of these compounds.

Infants Are Exposed to Human Milk Oligosaccharides Already in utero

Human milk oligosaccharides (HMOs) are complex carbohydrates that are highly abundant in and, in their complexity, unique to human milk. Accumulating evidence indicates that exposure to HMOs in the postnatal period affects immediate as well as long-term infant health and development. However, studies reported in the 1970s showed that HMOs already appear in maternal urine and blood during pregnancy and as early as the first trimester. In this pilot study we aimed to determine whether or not HMOs also appear in amniotic fluid. We enrolled women during pregnancy and collected their urine and amniotic fluid at birth as well as their milk 4 days postpartum. We analyzed the samples by high-performance liquid chromatography (HPLC) and mass spectrometry and identified several HMOs including 2'-fucosyllactose, 3-fucosyllactose, difucosyllactose, and 6'-sialyllactose to be present in different relative abundancies in all three tissues. This is the first report that HMOs appear in amniotic fluid and that the fetus is already exposed to HMOs in utero, warranting future research to investigate the immediate and long-term implications on fetal and infant health and development.

Maternal modifiers of the infant gut microbiota: metabolic consequences

Transmission of metabolic diseases from mother to child is multifactorial and includes genetic, epigenetic and environmental influences. Evidence in rodents, humans and non-human primates support the scientific premise that exposure to maternal obesity or high-fat diet during pregnancy creates a long-lasting metabolic signature on the infant innate immune system and the juvenile microbiota, which predisposes the offspring to obesity and metabolic diseases. In neonates, gastrointestinal microbes introduced through the mother are noted for their ability to serve as direct inducers/regulators of the infant immune system. Neonates have a limited capacity to initiate an immune response. Thus, disruption of microbial colonization during the early neonatal period results in disrupted postnatal immune responses that highlight the neonatal period as a critical developmental window. Although the mechanisms are poorly understood, increasing evidence suggests that maternal obesity or poor diet influences the development and modulation of the infant liver and other end organs through direct communication via the portal system, metabolite production, alterations in gut barrier integrity and the hematopoietic immune cell axis. This review will focus on how maternal obesity and dietary intake influence the composition of the infant gut microbiota and how an imbalance or maladaptation in the microbiota, including changes in early pioneering microbes, might contribute to the programming of offspring metabolism with special emphasis on mechanisms that promote chronic inflammation in the liver. Comprehension of these pathways and mechanisms will elucidate our understanding of developmental programming and may expand the avenue of opportunities for novel therapeutics.

Microbes in Infant Gut Development: Placing Abundance Within Environmental, Clinical and Growth Parameters

Sound and timely microbial gut colonization completes newborn’s healthy metabolic programming and manifests in infant appropriate growth and weight development. Feces, collected at 3, 30, and 90 days after birth from 60 breastfed Slovenian newborns, was submitted to microbial DNA extraction and qPCR quantification of selected gut associated taxa. Multivariate regression analysis was applied to evaluate microbial dynamics with respect to infant demographic, environmental, clinical characteristics and first year growth data. Early microbial variability was marked by the proportion of Bacilli, but diminished and converged in later samples, as bifidobacteria started to prevail. The first month proportions of enterococci were associated with maternity hospital locality and supplementation of breastfeeding with formulae, while Enterococcus faecalis proportion reflected the mode of delivery. Group Bacteroides-Prevotella proportion was associated with infant weight and ponderal index at first month. Infant mixed feeding pattern and health issues within the first month revealed the most profound and extended microbial perturbations. Our findings raise concerns over the ability of the early feeding supplementation to emulate and support the gut microbiota in a way similar to the exclusively breastfed infants. Additionally, practicing supplementation beyond the first month also manifested in higher first year weight and weight gain Z-score.

Overcoming the limited availability of human milk oligosaccharides: challenges and opportunities for research and application

Human milk oligosaccharides (HMOs) are complex sugars highly abundant in human milk but currently not present in infant formula. Rapidly accumulating evidence from in vitro and in vivo studies, combined with epidemiological associations and correlations, suggests that HMOs benefit infants through multiple mechanisms and in a variety of clinical contexts. Until recently, however, research on HMOs has been limited by an insufficient availability of HMOs. Most HMOs are found uniquely in human milk, and thus far it has been prohibitively tedious and expensive to isolate and synthesize them. This article reviews new strategies to overcome this lack of availability by generating HMOs through chemoenzymatic synthesis, microbial metabolic engineering, and isolation from human donor milk or dairy streams. Each approach has its advantages and comes with its own challenges, but combining the different methods and acknowledging their limitations creates new opportunities for research and application with the goal of improving maternal and infant health.

Human milk oligosaccharide categories define the microbiota composition in human colostrum

Human milk oligosaccharides (HMOs) are structurally diverse unconjugated glycans with a composition unique to each lactating mother. While HMOs have been shown to have an impact on the development of infant gut microbiota, it is not well known if HMOs also already affect milk microbial composition. To address this question, we analysed eleven colostrum samples for HMO content by high-pressure liquid chromatography and microbiota composition by quantitative PCR. Higher total HMO concentration was associated with higher counts of Bifidobacterium spp. (ρ=0.63, P=0.036). A distinctive effect was seen when comparing different HMO groups: positive correlations were observed between sialylated HMOs and Bifidobacterium breve (ρ=0.84, P=0.001), and non-fucosylated/non-sialylated HMOs and Bifidobacterium longum group (ρ=0.65, P=0.030). In addition to associations between HMOs and bifidobacteria, positive correlations were observed between fucosylated HMOs and Akkermansia muciniphila (ρ=0.70, P=0.017), and between fucosylated/sialylated HMOs and Staphylococcus aureus (ρ=0.75, P=0.007). Our results suggest that the characterised HMOs have an effect on specific microbial groups in human milk. Both oligosaccharides and microbes provide a concise inoculum for the compositional development of the infant gut microbiota.

Young microbes for adult obesity

Gut microbes are active participants of host metabolism. At birth, child physiology is committed towards healthiness or sickness depending, in part, on maternal condition (i.e. lean vs obesity) and delivery. Finally, changes from breastfeeding to solid food also account to define gut microbiota ecology in adulthood. Nowadays, alterations of gut microbiota, named dysbiosis, are acquired risk factors for multiple diseases, especially type 2 diabetes and obesity. Despite important evidence linking nutrition to dysbiosis to energetic dysmetabolism, molecular mechanisms for causality are still missing. That the status of gut microbiota of mother and child is crucial for future diseases is witnessed by adulthood overweight and obesity observed in children with dysbiosis. In this short review we highlight the importance of early life events related to the microbiota and their impact on future adult disease risk. Therefore, our effort to treat or prevent metabolic diseases should be addressed towards early or previous life steps, when microbial decisions are going to affect our metabolic fate.

The effect of simulated flash heating pasteurisation and Holder pasteurisation on human milk oligosaccharides

BACKGROUND

Human milk oligosaccharides (HMOs) have important protective functions in human milk. A low-cost remote pasteurisation temperature-monitoring system has been designed using FoneAstra, a cell phone-based networked sensing system to monitor simulated flash heat pasteurisation.

AIM

To compare the pasteurisation effect on HMOs of the FoneAstra FH method with the current Sterifeed Holder method used by human milk banks.

METHODS

Donor human milk samples (n = 48) were obtained from a human milk bank and pasteurised using the two pasteurisation methods. HMOs were purified from samples and labelled before separation using high-performance liquid chromatography. Concentrations of total HMOs, sialylated and fucosylated HMOs and individual HMOs using the two pasteurisation methods were compared using repeated-measures ANOVA.

RESULTS

The study demonstrated no difference in total concentration of HMOs between the two pasteurisation methods and a small but significant increase in the total concentration of HMOs regardless of pasteurisation methods compared with controls (unpasteurised samples) (p<0.0001).

CONCLUSION

The FoneAstra FH pasteurisation system does not negatively affect oligosaccharides in human milk and therefore is a possible alternative for providing safely sterilised human milk for low- and middle-income countries.

Prevention and Management of Cow's Milk Allergy in Non-Exclusively Breastfed Infants

Introduction: The prevention and management of cow milk allergy (CMA) is still debated. Since CMA is much less frequent in breastfed infants, breastfeeding should be stimulated. Method: Literature was searched using databases to find original papers and reviews on this topic. Results: Hydrolysates with a clinical proof of efficacy are recommended in the prevention and treatment of CMA. However, not all meta-analyses conclude that hydrolysates do prevent CMA or other atopic manifestations such as atopic dermatitis. There are pros and cons to consider partially hydrolysed protein as an option for starter infant formula for each non-exclusively breastfed infant. A challenge test is still recommended as the most specific and sensitive diagnostic test, although a positive challenge test does not proof that the immune system is involved. The Cow Milk Symptom Score (CoMiSS™) is an awareness tool that enables healthcare professionals to better recognize symptoms related to the ingestion of cow milk, but it still needs validation as diagnostic tool. The current recommended elimination diet is a cow milk based extensive hydrolysate, although rice hydrolysates or soy infant formula can be considered in some cases. About 10 to 15% of infants allergic to cow milk will also react to soy. Mainly because of the higher cost, amino acid based formula is reserved for severe cases. There is no place for infant formula with intact protein from other animals as cross-over allergenicity is high. During recent years, attention focused also on the bifidogenic effect of prebiotics and more recently also on human milk oligosaccharides. A bifidogenic gastrointestinal microbiome may decrease the risk to develop allergic disease. The addition of probiotics and prebiotics to the elimination diet in treatment may enhance the development of tolerance development. Conclusion: Breastfeeding is the best way to feed infants. Cow milk based extensive hydrolysates remain the first option for the treatment of CMA for the majority of patients, while amino acid formulas are reserved for the most severe cases. Rice hydrolysates and soy infant formula are second choice options. Partial hydrolysates with clinical proof of efficacy are recommended in some guidelines in the prevention of CMA and allergic disease in at risk infants, and may be considered as an option as protein source in starter infant formula.

What's normal? Oligosaccharide concentrations and profiles in milk produced by healthy women vary geographically

Background: Human milk is a complex fluid comprised of myriad substances, with one of the most abundant substances being a group of complex carbohydrates referred to as human milk oligosaccharides (HMOs). There has been some evidence that HMO profiles differ in populations, but few studies have rigorously explored this variability.Objectives: We tested the hypothesis that HMO profiles differ in diverse populations of healthy women. Next, we examined relations between HMO and maternal anthropometric and reproductive indexes and indirectly examined whether differences were likely related to genetic or environmental variations.Design: In this cross-sectional, observational study, milk was collected from a total of 410 healthy, breastfeeding women in 11 international cohorts and analyzed for HMOs by using high-performance liquid chromatography.Results: There was an effect of the cohort (P < 0.05) on concentrations of almost all HMOs. For instance, the mean 3-fucosyllactose concentration was >4 times higher in milk collected in Sweden than in milk collected in rural Gambia (mean ± SEM: 473 ± 55 compared with 103 ± 16 nmol/mL, respectively; P < 0.05), and disialyllacto-N-tetraose (DSLNT) concentrations ranged from 216 ± 14 nmol/mL (in Sweden) to 870 ± 68 nmol/mL (in rural Gambia) (P < 0.05). Maternal age, time postpartum, weight, and body mass index were all correlated with several HMOs, and multiple differences in HMOs [e.g., lacto-N-neotetrose and DSLNT] were shown between ethnically similar (and likely genetically similar) populations who were living in different locations, which suggests that the environment may play a role in regulating the synthesis of HMOs.Conclusions: The results of this study support our hypothesis that normal HMO concentrations and profiles vary geographically, even in healthy women. Targeted genomic analyses are required to determine whether these differences are due at least in part to genetic variation. A careful examination of sociocultural, behavioral, and environmental factors is needed to determine their roles in this regard. This study was registered at clinicaltrials.gov as NCT02670278.

Human Milk Oligosaccharides and the Preterm Infant: A Journey in Sickness and in Health

Human milk oligosaccharides (HMOs) are a group of approximately 200 different unconjugated sugar structures in human milk proposed to support infant growth and development. Data from several preclinical animal studies and human cohort studies suggest HMOs reduce preterm infant mortality and morbidity by shaping the gut microbiome and protecting against necrotizing enterocolitis, candidiasis, and several other immune-related diseases. Current feeding practices and clinical algorithms do not consider infant HMO intake when assessing dietary adequacy or disease risk. Advancements in HMO analytical methodologies and HMO synthesis facilitate cohort and intervention studies to investigate which particular HMOs are most relevant in supporting preterm infants.

Fructose in Breast Milk Is Positively Associated with Infant Body Composition at 6 Months of Age

Dietary sugars have been shown to promote excess adiposity among children and adults; however, no study has examined fructose in human milk and its effects on body composition during infancy. Twenty-five mother–infant dyads attended clinical visits to the Oklahoma Health Sciences Center at 1 and 6 months of infant age. Infants were exclusively breastfed for 6 months and sugars in breast milk (i.e., fructose, glucose, lactose) were measured by Liquid chromatography-mass spectrometry (LC-MS/MS) and glucose oxidase. Infant body composition was assessed using dual-energy X-ray absorptiometry at 1 and 6 months. Multiple linear regression was used to examine associations between breast milk sugars and infant body composition at 6 months of age. Fructose, glucose, and lactose were present in breast milk and stable across visits (means = 6.7 μg/mL, 255.2 μg/mL, and 7.6 g/dL, respectively). Despite its very low concentration, fructose was the only sugar significantly associated with infant body composition. A 1-μg/mL higher breast milk fructose was associated with a 257 g higher body weight (p = 0.02), 170 g higher lean mass (p = 0.01), 131 g higher fat mass (p = 0.05), and 5 g higher bone mineral content (p = 0.03). In conclusion, fructose is detectable in human breast milk and is positively associated with all components of body composition at 6 months of age.

Relationship Between Exclusive Breastfeeding and Lower Risk of Childhood Obesity: A Narrative Review of Published Evidence

BACKGROUND

The pattern of infant feeding during the first 1000-day period-from conception to the second birthday-has a significant influence on the child's growth trajectory. The relationship between exclusive breastfeeding and lower risk of childhood obesity has elicited much scientific interest, given the fact that this form of malnutrition is becoming a global epidemic.

AIM

This narrative review aims to examine the evidence in the literature linking exclusive breastfeeding with reduction in obesity in children.

LITERATURE SEARCH

Using appropriate search terms, PubMed database was searched for relevant articles that met the review objective.

RESULTS

Evidence for the protective effect of exclusive breastfeeding against childhood obesity have been provided by studies which explored 5 physiologic mechanisms and those that established the causality between breastfeeding and lower risk of obesity. The few studies that disputed this relationship highlighted the influence of confounding factors. A new insight on molecular mechanisms, however, points to a direct and indirect effect of human milk oligosaccharides on the prevention of overweight and obesity.

CONCLUSIONS

The preponderance of current evidence strongly suggests that exclusivity in breastfeeding can prevent the development of obesity in children.

Longitudinal change of selected human milk oligosaccharides and association to infants' growth, an observatory, single center, longitudinal cohort study

Background

Human milk is the recommended and sole nutrient source for newborns. One of the largest components of human milk is oligosaccharides (HMOs) with major constituents determined by the mother genotype for the fucosyltransferase 2 (FUT2, secretor) gene. HMO variation has been related with infant microbiota establishment, diarrhea incidence, morbidity and mortality, IgE associated eczema and body composition.

Objectives

We investigated the (i) dependence of several major representative HMOs on the FUT2 status assessed through breast milk 2’Fucosyllactose (2’FL) and (ii) the relation of the 2’FL status with infant growth up to 4 months of life.

Design

From an open observatory, single center, longitudinal cohort study with quantitative human milk collection at 30, 60, and 120 days postpartum from 50 mothers, who gave birth to 25 female and 25 male singleton infants, we collected a representative sample of human milk. We quantified the following 5 representative HMOs: 2’FL, Lacto-N-tetraose (LNT), Lacto-N-neotetraose (LNnT), 3’Sialyllactose (3’SL) and 6’Sialyllactose (6’SL). We grouped the milk samples and corresponding infants according to the measured milk 2’FL concentrations at 30 days of lactation, which clustered around low concentrations (95% CI of mean 12–42 mg/L) and high concentrations (95% CI of mean 1880–2460 mg/L) with the former likely representing Secretor negative mothers. Infant anthropometric measures were recorded at birth, 1, 2 and 4 months of age. Relations among the quantified HMOs and the relation of the high and low 2’FL HMOs groups with infant growth parameters were investigated via linear mixed models.

Results

The milk samples with low 2’FL concentration had higher LNT and lower LNnT concentrations compared to the samples with high 2’FL. The milk 3’- and 6’SL concentrations were independent of 2’FL. Over lactation time we observed a drop in the concentration of 2’FL, LNT, LNnT and 6’SL, especially from 1 to 2 months, while 3’SL remained at relatively constant concentration from 1 month onwards. Up to 4 months of age, we did not observe significant differences in body weight, body length, body mass index and head circumference of the infants who consumed breast milk with low or high FUT2 associated HMO concentrations and composition.

Conclusions

Our findings on HMO concentrations over time of lactation and clusters based on 2’FL concentrations confirm previous observations and suggest that LNnT and LNT are ‘co-regulated’ with the FUT2 dependent 2’FL concentration, with LNnT showing a positive and LNT a negative relation. Further, our findings also suggest that the relatively substantial variation in HMOs between the high and low 2’FL clusters do not impact infant growth of either sex up to 4 months of age. The study was registered in www.ClinicalTrial.gov (NCT01805011).

Obesity and pregnancy: mechanisms of short term and long term adverse consequences for mother and child

Obesity is the most common medical condition in women of reproductive age. Obesity during pregnancy has short term and long term adverse consequences for both mother and child. Obesity causes problems with infertility, and in early gestation it causes spontaneous pregnancy loss and congenital anomalies. Metabolically, obese women have increased insulin resistance in early pregnancy, which becomes manifest clinically in late gestation as glucose intolerance and fetal overgrowth. At term, the risk of cesarean delivery and wound complications is increased. Postpartum, obese women have an increased risk of venous thromboembolism, depression, and difficulty with breast feeding. Because 50-60% of overweight or obese women gain more than recommended by Institute of Medicine gestational weight guidelines, postpartum weight retention increases future cardiometabolic risks and prepregnancy obesity in subsequent pregnancies. Neonates of obese women have increased body fat at birth, which increases the risk of childhood obesity. Although there is no unifying mechanism responsible for the adverse perinatal outcomes associated with maternal obesity, on the basis of the available data, increased prepregnancy maternal insulin resistance and accompanying hyperinsulinemia, inflammation, and oxidative stress seem to contribute to early placental and fetal dysfunction. We will review the pathophysiology underlying these data and try to shed light on the specific underlying mechanisms.

Leptin Levels Are Higher in Whole Compared to Skim Human Milk, Supporting a Cellular Contribution

Human milk (HM) contains a plethora of metabolic hormones, including leptin, which is thought to participate in the regulation of the appetite of the developing infant. Leptin in HM is derived from a combination of de novo mammary synthesis and transfer from the maternal serum. Moreover, leptin is partially lipophilic and is also present in HM cells. However, leptin has predominately been measured in skim HM, which contains neither fat nor cells. We optimised an enzyme-linked immunosorbent assay for leptin measurement in both whole and skim HM and compared leptin levels between both HM preparations collected from 61 lactating mothers. Whole HM leptin ranged from 0.2 to 1.47 ng/mL, whilst skim HM leptin ranged from 0.19 to 0.9 ng/mL. Whole HM contained, on average, 0.24 ± 0.01 ng/mL more leptin than skim HM (p < 0.0001, n = 287). No association was found between whole HM leptin and fat content (p = 0.17, n = 287), supporting a cellular contribution to HM leptin. No difference was found between pre- and post-feed samples (whole HM: p = 0.29, skim HM: p = 0.89). These findings highlight the importance of optimising HM leptin measurement and assaying it in whole HM to accurately examine the amount of leptin received by the infant during breastfeeding.

Challenges of infant nutrition research: a commentary

Considerable advances have been made in the field of infant feeding research. The last few decades have witnessed the expansion in the number of studies on the composition and benefits of human milk. The practice of breastfeeding and use of human milk represent today’s reference standards for infant feeding and nutrition. Additional research regarding the benefits of breastfeeding is needed to determine which factors in human milk and in the act of breastfeeding itself, singly or in combination, are most important for producing the beneficial effects on infant growth, body composition, and neurodevelopmental outcome. We examine evidence that breastfeeding confers health benefits and offer suggestions on how best to interpret the data and present it to the public. We also describe some examples of well-designed infant nutrition studies that provide useful and clinically meaningful data regarding infant feeding, growth, and development. Because not all mothers choose to breastfeed or can breastfeed, other appropriate feeding options should be subjected to critical review to help establish how infant formula and bottle feeding can confer benefits similar to those of human milk and the act of breastfeeding. We conclude with the overarching point that the goal of infant feeding research is to promote optimal infant growth and development. Since parents/families may take different paths to feeding their infants, it is fundamental that health professionals understand how best to interpret research studies and their findings to support optimal infant growth and development.