Human Milk Oligosaccharides (HMOs) and Infant Microbiota: A Scoping Review

Human milk oligosaccharides (HMOs) are the third most abundant solid component of breast milk. However, the newborn cannot assimilate them as nutrients. They are recognized prebiotic agents (the first in the newborn diet) that stimulate the growth of beneficial microorganisms, mainly the genus Bifidobacterium, dominant in the gut of breastfed infants. The structures of the oligosaccharides vary mainly according to maternal genetics, but also other maternal factors such as parity and mode of delivery, age, diet, and nutritional status or even geographic location and seasonality cause different breast milk oligosaccharides profiles. Differences in the profiles of HMO have been linked to breast milk microbiota and gut microbial colonization of babies. Here, we provide a review of the scope of reports on associations between HMOs and the infant gut microbiota to assess the impact of HMO composition.

Download Full-text

New strategies for profiling and characterization of human milk oligosaccharides

Glycobiology ◽

10.1093/glycob/cwaa028 ◽

2020 ◽

Vol 30 (10) ◽

pp. 774-786 ◽

Cited By ~ 1

Author(s):

Sara Porfirio ◽

Stephanie Archer-Hartmann ◽

G Brett Moreau ◽

Girija Ramakrishnan ◽

Rashidul Haque ◽

...

Keyword(s):

Breast Milk ◽

Human Milk ◽

Milk Composition ◽

Human Breast Milk ◽

Human Milk Oligosaccharides ◽

Bacterial Strains ◽

Milk Oligosaccharides ◽

Vast Number ◽

The Impact

Abstract Human breast milk is an incredibly rich and complex biofluid composed of proteins, lipids and complex carbohydrates, including a diverse repertoire of free human milk oligosaccharides (HMOs). Strikingly, HMOs are not digested by the infant but function as prebiotics for bacterial strains associated with numerous benefits. Considering the broad variety of beneficial effects of HMOs, and the vast number of factors that affect breast milk composition, the analysis of HMO diversity and complexity is of utmost relevance. Using human milk samples from a cohort of Bangladeshi mothers participating in a study on malnutrition and stunting in children, we have characterized breast milk oligosaccharide composition by means of permethylation followed by liquid chromatography coupled with high-resolution tandem mass spectrometry (LC-MS/MS) analysis. This approach identified over 100 different glycoforms and showed a wide diversity of milk composition, with a predominance of fucosylated and sialylated HMOs over nonmodified HMOs. We observed that these samples contain on average 80 HMOs, with the highest permethylated masses detected being >5000 mass units. Here we report an easily implemented method developed for the separation, characterization and relative quantitation of large arrays of HMOs, including higher molecular weight sialylated HMOs. Our ultimate goal is to create a simple, high-throughput method, which can be used for full characterization of sialylated and/or fucosylated HMOs. These results demonstrate how current analytical techniques can be applied to characterize human milk composition, providing new tools to help the scientific community shed new light on the impact of HMOs during infant development.

Download Full-text

Profiles of Human Milk Oligosaccharides and Their Relations to the Milk Microbiota of Breastfeeding Mothers in Dubai

Nutrients ◽

10.3390/nu12061727 ◽

2020 ◽

Vol 12 (6) ◽

pp. 1727

Author(s):

Carole Ayoub Moubareck ◽

Maryam Lootah ◽

Muna Tahlak ◽

Koen Venema

Keyword(s):

Breast Milk ◽

Human Milk ◽

Maternal Nutrition ◽

Geographic Location ◽

Rrna Gene ◽

Human Breast Milk ◽

Lactation Period ◽

Human Milk Oligosaccharides ◽

Microbial Composition ◽

Milk Oligosaccharides

The composition of human breast milk is affected by several factors, including genetics, geographic location and maternal nutrition. This study investigated the human milk oligosaccharides (HMOs) of breastfeeding mothers living in Dubai and their relations with the milk microbiota. A total of 30 breast milk samples were collected from healthy Emirati and UAE-expatriates at Latifa Hospital. HMO profiling was performed using UHPLC-MS. Microbiota profiles were determined by sequencing amplicons of the V3-V4 region of the 16S rRNA gene. HMO concentrations were significantly higher in Emirati, and dropped with the lactation period in both groups of mothers. The Le (a−b+)-secretor (Le+Se+) type was the most abundant in Dubai mothers (60%), followed by the Le(a−b−)-secretor (Le−Se+) type (23%). Bifidobacterium and Lactobacillus were considerably lower in Dubai-based mothers, while Pseudomonas and Delftia (Hydrogenophaga) were detected at a higher abundance compared to mothers from other countries. Atopobium was correlated with sialyl-lacto-N-tetraose c, Leptotrichia and Veillonella were correlated with 6’-sialyl-lactose, and Porphyromonas was correlated with lacto-N-hexaose. The study highlights the HMO profiles of breastfeeding mothers in Dubai and reveals few correlations with milk microbial composition. Targeted genomic analyses may help in determining whether these differences are due to genetic variations or to sociocultural and environmental factors.

Download Full-text

Associations between human milk oligosaccharides and growth in infancy and early childhood

American Journal of Clinical Nutrition ◽

10.1093/ajcn/nqaa010 ◽

2020 ◽

Vol 111 (4) ◽

pp. 769-778 ◽

Cited By ~ 10

Author(s):

Hanna Lagström ◽

Samuli Rautava ◽

Helena Ollila ◽

Anne Kaljonen ◽

Olli Turta ◽

...

Keyword(s):

Human Milk ◽

Causal Relation ◽

Mode Of Delivery ◽

Child Growth ◽

Birth Cohort Study ◽

Human Milk Oligosaccharides ◽

Milk Oligosaccharides ◽

Milk Samples ◽

Prepregnancy Bmi ◽

The Impact

ABSTRACT Background Breastfeeding modulates infant growth and protects against the development of obesity. However, whether or not maternal variation in human milk components, such as human milk oligosaccharides (HMOs), is associated with programming of child growth remains unknown. Objective Our objective was to determine the association between maternal HMO composition and child growth during the first 5 y of life. In addition, the association between maternal prepregnancy BMI and HMO composition was assessed. Methods Human milk samples from 802 mothers were obtained from a prospective population-based birth cohort study, Steps to healthy development of Children (STEPS), conducted in Turku, Finland. HMO composition in these milk samples was analyzed by HPLC. Child growth data from 3 mo to 5 y were collected from municipal well-baby clinics and linked to maternal HMO composition data to test for associations. Results Maternal HMO composition 3 mo after delivery was associated with height and weight during the first 5 y of life in children of secretor mothers. Specifically, HMO diversity and the concentration of lacto-N-neo-tetraose (LNnT) were inversely associated and that of 2′-fucosyllactose (2′FL) was directly associated with child height and weight z scores in a model adjusted for maternal prepregnancy BMI, mode of delivery, birthweight z score, sex, and time. Maternal prepregnancy BMI was associated with HMO composition. Conclusions The association between maternal HMO composition and childhood growth may imply a causal relation, which warrants additional testing in preclinical and clinical studies, especially since 2′FL and LNnT are among the HMOs now being added to infant formula. Furthermore, altered HMO composition may mediate the impact of maternal prepregnancy BMI on childhood obesity, which warrants further investigation to establish the cause-and-effect relation.

Download Full-text

Does the contribution of human milk oligosaccharides to the beneficial effects of breast milk allow us to hope for an improvement in infant formulas?

Critical Reviews in Food Science and Nutrition ◽

10.1080/10408398.2020.1761772 ◽

2020 ◽

pp. 1-12

Author(s):

Jean-Pierre Chouraqui

Keyword(s):

Breast Milk ◽

Human Milk ◽

Infant Formulas ◽

Human Milk Oligosaccharides ◽

Milk Oligosaccharides ◽

Beneficial Effects

Download Full-text

Diversification of a fucosyllactose transporter within the genus Bifidobacterium

Applied and Environmental Microbiology ◽

10.1128/aem.01437-21 ◽

2021 ◽

Author(s):

Miriam N. Ojima ◽

Yuya Asao ◽

Aruto Nakajima ◽

Toshihiko Katoh ◽

Motomitsu Kitaoka ◽

...

Keyword(s):

Human Milk ◽

Binding Proteins ◽

Heterologous Gene Expression ◽

Metagenomic Data ◽

Dependent Manner ◽

Human Milk Oligosaccharides ◽

Milk Oligosaccharides ◽

Formula Milk ◽

Breastfed Infants ◽

Strain Dependent

Human milk oligosaccharides (HMOs), which are natural bifidogenic prebiotics, were recently commercialized to fortify formula milk. However, HMO-assimilation phenotypes of bifidobacteria vary by species and strain, which has not been fully linked to strain genotype. We have recently shown that specialized uptake systems, particularly for the internalization of major HMOs (fucosyllactose (FL)), are associated with the formation of a bifidobacteria-rich gut microbial community. Phylogenetic analysis has revealed that FL transporters have diversified into two clades harboring four clusters within the Bifidobacterium genus, but the underpinning functional diversity associated with this divergence remains underexplored. In this study, we examined the HMO-consumption phenotypes of two bifidobacterial species, Bifidobacterium catenulatum subspecies kashiwanohense and Bifidobacterium pseudocatenulatum , which both possess FL binding proteins that belong to phylogenetic clusters with unknown specificities. Growth assays, heterologous gene expression experiments, and HMO-consumption analysis showed that the FL transporter type from B. catenulatum subspecies kashiwanohense JCM 15439 T conferred a novel HMO-uptake pattern that includes the complex fucosylated HMOs (lacto- N- fucopentaose II and lacto- N- difucohexaose I/II). Further genomic landscape analyses of FL transporter-positive bifidobacterial strains revealed that H-antigen or Lewis antigen-specific fucosidase gene(s) and FL transporter specificities were largely aligned. These results suggest that bifidobacteria have acquired FL transporters along with the corresponding gene sets necessary to utilize the imported HMOs. Our results provide insight into the species- and strain-dependent adaptation strategies of bifidobacteria to HMO-rich environments. Importance The gut of breastfed infants is generally dominated by health-promoting bifidobacteria. Human milk oligosaccharides (HMOs) from breastmilk selectively promote the growth of specific taxa such as bifidobacteria, thus forming an HMO-mediated, host-microbe symbiosis. While the co-evolution of humans and bifidobacteria has been proposed, the underpinning adaptive strategies employed by bifidobacteria require further research. Here, we analyzed the divergence of the critical fucosyllactose (FL) HMO transporter within Bifidobacterium . We have shown that the diversification of the solute-binding proteins of the FL-transporter led to uptake specificities of fucosylated sugars ranging from simple trisaccharides to complex hexasaccharides. This transporter and the congruent acquisition of the necessary intracellular enzymes allows for bifidobacteria to import different types of HMOs in a predictable and strain-dependent manner. These findings explain the adaptation and proliferation of bifidobacteria in the competitive and HMO-rich infant gut environment and enable accurate specificity annotation of transporters from metagenomic data.

Download Full-text

Low Diversity of Human Milk Oligosaccharides is Associated with Necrotising Enterocolitis in Extremely Low Birth Weight Infants

Nutrients ◽

10.3390/nu10101556 ◽

2018 ◽

Vol 10 (10) ◽

pp. 1556 ◽

Cited By ~ 10

Author(s):

Erik Wejryd ◽

Magalí Martí ◽

Giovanna Marchini ◽

Anna Werme ◽

Baldvin Jonsson ◽

...

Keyword(s):

Birth Weight ◽

Breast Milk ◽

Low Birth Weight ◽

Human Milk ◽

Amperometric Detection ◽

Exchange Chromatography ◽

Extremely Low Birth Weight ◽

Human Milk Oligosaccharides ◽

Low Birth Weight Infants ◽

Milk Oligosaccharides

Difference in human milk oligosaccharides (HMO) composition in breast milk may be one explanation why some preterm infants develop necrotizing enterocolitis (NEC) despite being fed exclusively with breast milk. The aim of this study was to measure the concentration of 15 dominant HMOs in breast milk during the neonatal period and investigate how their levels correlated to NEC, sepsis, and growth in extremely low birth weight (ELBW; <1000 g) infants who were exclusively fed with breast milk. Milk was collected from 91 mothers to 106 infants at 14 and 28 days and at postmenstrual week 36. The HMOs were analysed with high-performance anion-exchange chromatography with pulsed amperometric detection. The HMOs diversity and the levels of Lacto-N-difucohexaose I were lower in samples from mothers to NEC cases, as compared to non-NEC cases at all sampling time points. Lacto-N-difucohexaose I is only produced by secretor and Lewis positive mothers. There were also significant but inconsistent associations between 3′-sialyllactose and 6′-sialyllactose and culture-proven sepsis and significant, but weak correlations between several HMOs and growth rate. Our results suggest that the variation in HMO composition in breast milk may be an important factor explaining why exclusively breast milk fed ELBW infants develop NEC.

Download Full-text

Efforts to emulate human milk oligosaccharides

British Journal Of Nutrition ◽

10.1017/s0007114507838062 ◽

2007 ◽

Vol 98 (S1) ◽

pp. S74-S79 ◽

Cited By ~ 21

Author(s):

Rosa María Espinosa ◽

Martha Taméz ◽

Pedro Prieto

Keyword(s):

Breast Milk ◽

Human Milk ◽

Current Knowledge ◽

Biological Effects ◽

Historical Context ◽

Published Data ◽

Human Milk Oligosaccharides ◽

Milk Oligosaccharides ◽

Fast Analysis ◽

Chemical Structures

Research on human milk oligosaccharides (HMO) began with the characterisation of their chemical structures and is now focused on the elucidation of their biological roles. Previously, biological effects could only be investigated with fractions or structures isolated from breast milk; consequently, clinical observations were limited to comparisons between outcomes from breast-fed infants and their formula-fed counterparts. In some cases, it was inferred that the observed differences were caused by the presence of HMO in breast milk. Presently, analytical techniques allow for the fast analysis of milk samples, thus providing insights on the inherent variability of specimens. In addition, methods for the synthesis of HMO have provided single structures in sufficient quantities to perform clinical studies with oligosaccharide-supplemented formulae. Furthermore, studies have been conducted with non-mammalian oligosaccharides with the purpose of assessing the suitability of these structures to functionally emulate HMO. Taken together, these developments justify summarising current knowledge on HMO to further discussions on efforts to emulate human milk in regard to its oligosaccharide content. The present account summarises published data and intends to provide an historical context and to illustrate the state of the field.

Download Full-text

The Role of Human Milk Oligosaccharides and Probiotics on the Neonatal Microbiome and Risk of Necrotizing Enterocolitis: A Narrative Review

Nutrients ◽

10.3390/nu12103052 ◽

2020 ◽

Vol 12 (10) ◽

pp. 3052

Author(s):

Lila S. Nolan ◽

Jamie M. Rimer ◽

Misty Good

Keyword(s):

Human Milk ◽

Preterm Infants ◽

Necrotizing Enterocolitis ◽

Mode Of Delivery ◽

Intestinal Barrier ◽

Vulnerable Population ◽

Human Milk Oligosaccharides ◽

Milk Oligosaccharides ◽

Intestinal Homeostasis

Preterm infants are a vulnerable population at risk of intestinal dysbiosis. The newborn microbiome is dominated by Bifidobacterium species, though abnormal microbial colonization can occur by exogenous factors such as mode of delivery, formula feeding, and exposure to antibiotics. Therefore, preterm infants are predisposed to sepsis and necrotizing enterocolitis (NEC), a fatal gastrointestinal disorder, due to an impaired intestinal barrier, immature immunity, and a dysbiotic gut microbiome. Properties of human milk serve as protection in the prevention of NEC. Human milk oligosaccharides (HMOs) and the microbiome of breast milk are immunomodulatory components that provide intestinal homeostasis through regulation of the microbiome and protection of the intestinal barrier. Enteral probiotic supplements have been trialed to evaluate their impact on establishing intestinal homeostasis. Here, we review the protective role of HMOs, probiotics, and synbiotic combinations in protecting a vulnerable population from the pathogenic features associated with necrotizing enterocolitis.

Download Full-text

Influence of sulfonated and diet-derived human milk oligosaccharides on the infant microbiome and immune markers

Journal of Biological Chemistry ◽

10.1074/jbc.ra119.011351 ◽

2020 ◽

Vol 295 (12) ◽

pp. 4035-4048 ◽

Cited By ~ 4

Author(s):

Candice Quin ◽

Sara D. Vicaretti ◽

Nina A Mohtarudin ◽

Alexander M. Garner ◽

Deanna M. Vollman ◽

...

Keyword(s):

Fatty Acids ◽

Breast Milk ◽

Human Milk ◽

Unsaturated Fatty Acids ◽

Maternal Diet ◽

Intestinal Microbiome ◽

Human Milk Oligosaccharides ◽

Immune Markers ◽

Milk Oligosaccharides ◽

Milk Fatty Acids

Human milk oligosaccharides (HMOs) promote the development of the neonatal intestinal, immune, and nervous systems and has recently received considerable attention. Here we investigated how the maternal diet affects HMO biosynthesis and how any diet-induced HMO alterations influence the infant gut microbiome and immunity. Using capillary electrophoresis and MS-based analyses, we extracted and measured HMOs from breast milk samples and then correlated their levels with results from validated 24-h diet recall surveys and breast milk fatty acids. We found that fruit intake and unsaturated fatty acids in breast milk were positively correlated with an increased absolute abundance of numerous HMOs, including 16 sulfonated HMOs we identified here in humans for the first time. The diet-derived monosaccharide 5-N-glycolyl-neuraminic acid (Neu5Gc) was unambiguously detected in all samples. To gain insights into the potential impact of Neu5Gc on the infant microbiome, we used a constrained ordination approach and identified correlations between Neu5Gc levels and Bacteroides spp. in infant stool. However, Neu5Gc was not associated with marked changes in infant immune markers, in contrast with sulfonated HMOs, whose expression correlated with suppression of two major Th2 cytokines, IL-10 and IL-13. The findings of our work highlight the importance of maternal diet for HMO biosynthesis and provide as yet unexplored targets for future studies investigating interactions between HMOs and the intestinal microbiome and immunity in infants.

Download Full-text