scholarly journals Screening natural libraries of human milk oligosaccharides against lectins using CaR-ESI-MS

The Analyst ◽  
2018 ◽  
Vol 143 (2) ◽  
pp. 536-548 ◽  
Author(s):  
Amr El-Hawiet ◽  
Yajie Chen ◽  
Km Shams-Ud-Doha ◽  
Elena N. Kitova ◽  
Pavel I. Kitov ◽  
...  

Human milk oligosaccharides (HMOs) afford many health benefits to breast-fed infants, such as protection against infection and regulation of the immune system, through the formation of non-covalent interactions with protein receptors.

mSystems ◽  
2018 ◽  
Vol 3 (6) ◽  
Author(s):  
Yaqiang Bai ◽  
Jia Tao ◽  
Jiaorui Zhou ◽  
Qingjie Fan ◽  
Man Liu ◽  
...  

ABSTRACT The milk glycobiome has a significant impact on the gut microbiota of infants, which plays a pivotal role in health and development. Fucosylated human milk oligosaccharides (HMOs) and N-glycans on milk proteins are beneficial for the development of healthy gut microbiota, and the fucosylation levels of these glycans can be affected by the maternal fucosyltransferase 2 gene (FUT2). Here, we present results of longitudinal research on paired milk and stool samples from 56 Chinese mothers (CMs) and their breast-fed children. Changes of HMOs and fucosylated N-glycans in milk of CMs at different lactation stages were detected, which allowed characterization of the major differences in milk glycans and consequential effects on the gut microbiome of infants according to maternal FUT2 status. Significant differences in the abundance of total and fucosylated HMOs between secretor and nonsecretor CMs were noted, especially during early lactation. Despite a tendency toward decreasing milk protein concentrations, the fucosylation levels of milk N-glycans increased during late lactation. The changes in the levels of fucosylated HMOs and milk N-glycans were highly correlated with the growth of Bifidobacterium spp. and Lactobacillus spp. in the gut of infants during early and later lactation, respectively. Enriched expression of genes encoding glycoside hydrolases, glycosyl transferases, ATP-binding cassette (ABC) transporters, and permeases in infants fed by secretor CMs contributed to the promotion of these bacteria in infants. Our data highlight the important role of fucosylated milk glycans in shaping the gut microbiome of infants and provide a solid foundation for development of “personalized” nutrition for Chinese infants. IMPORTANCE Human milk glycans provide a broad range of carbon sources for gut microbes in infants. Levels of protein glycosylation in human milk vary during lactation and may also be affected by the stages of gestation and lactation and by the secretor status of the mother. This was the first study to evaluate systematically dynamic changes in human milk oligosaccharides and fucosylated N-glycans in the milk of Chinese mothers with different secretor statuses during 6 months of lactation. Given the unique single nucleotide polymorphism site (rs1047781, A385T) on the fucosyltransferase 2 gene among Chinese populations, our report provides a specific insight into the milk glycobiome of Chinese mothers, which may exert effects on the gut microbiota of infants that differ from findings from other study cohorts.


2013 ◽  
Vol 79 (19) ◽  
pp. 6040-6049 ◽  
Author(s):  
Santiago Ruiz-Moyano ◽  
Sarah M. Totten ◽  
Daniel A. Garrido ◽  
Jennifer T. Smilowitz ◽  
J. Bruce German ◽  
...  

ABSTRACTHuman milk contains a high concentration of complex oligosaccharides that influence the composition of the intestinal microbiota in breast-fed infants. Previous studies have indicated that select species such asBifidobacterium longumsubsp.infantisandBifidobacterium bifidumcan utilize human milk oligosaccharides (HMO)in vitroas the sole carbon source, while the relatively fewB. longumsubsp.longumandBifidobacterium breveisolates tested appear less adapted to these substrates. Considering the high frequency at whichB. breveis isolated from breast-fed infant feces, we postulated that someB. brevestrains can more vigorously consume HMO and thus are enriched in the breast-fed infant gastrointestinal tract. To examine this, a number ofB. breveisolates from breast-fed infant feces were characterized for the presence of different glycosyl hydrolases that participate in HMO utilization, as well as by their ability to grow on HMO or specific HMO species such as lacto-N-tetraose (LNT) and fucosyllactose. AllB. brevestrains showed high levels of growth on LNT and lacto-N-neotetraose (LNnT), and, in general, growth on total HMO was moderate for most of the strains, with several strain differences. Growth and consumption of fucosylated HMO were strain dependent, mostly in isolates possessing a glycosyl hydrolase family 29 α-fucosidase. Glycoprofiling of the spent supernatant after HMO fermentation by select strains revealed that allB. brevestrains can utilize sialylated HMO to a certain extent, especially sialyl-lacto-N-tetraose. Interestingly, this specific oligosaccharide was depleted before neutral LNT by strain SC95. In aggregate, this work indicates that the HMO consumption phenotype inB. breveis variable; however, some strains display specific adaptations to these substrates, enabling more vigorous consumption of fucosylated and sialylated HMO. These results provide a rationale for the predominance of this species in breast-fed infant feces and contribute to a more accurate picture of the ecology of the developing infant intestinal microbiota.


2019 ◽  
Vol 14 (2) ◽  
pp. 635-648 ◽  
Author(s):  
Melissa A. E. Lawson ◽  
Ian J. O’Neill ◽  
Magdalena Kujawska ◽  
Sree Gowrinadh Javvadi ◽  
Anisha Wijeyesekera ◽  
...  

AbstractDiet-microbe interactions play an important role in modulating the early-life microbiota, with Bifidobacterium strains and species dominating the gut of breast-fed infants. Here, we sought to explore how infant diet drives distinct bifidobacterial community composition and dynamics within individual infant ecosystems. Genomic characterisation of 19 strains isolated from breast-fed infants revealed a diverse genomic architecture enriched in carbohydrate metabolism genes, which was distinct to each strain, but collectively formed a pangenome across infants. Presence of gene clusters implicated in digestion of human milk oligosaccharides (HMOs) varied between species, with growth studies indicating that within single infants there were differences in the ability to utilise 2′FL and LNnT HMOs between strains. Cross-feeding experiments were performed with HMO degraders and non-HMO users (using spent or ‘conditioned’ media and direct co-culture). Further 1H-NMR analysis identified fucose, galactose, acetate, and N-acetylglucosamine as key by-products of HMO metabolism; as demonstrated by modest growth of non-HMO users on spend media from HMO metabolism. These experiments indicate how HMO metabolism permits the sharing of resources to maximise nutrient consumption from the diet and highlights the cooperative nature of bifidobacterial strains and their role as ‘foundation’ species in the infant ecosystem. The intra- and inter-infant bifidobacterial community behaviour may contribute to the diversity and dominance of Bifidobacterium in early life and suggests avenues for future development of new diet and microbiota-based therapies to promote infant health.


2014 ◽  
Vol 59 (2) ◽  
pp. 355-364 ◽  
Author(s):  
Viktoria Dotz ◽  
Silvia Rudloff ◽  
Christina Meyer ◽  
Günter Lochnit ◽  
Clemens Kunz

2013 ◽  
Vol 110 (4) ◽  
pp. 640-650 ◽  
Author(s):  
Evelyn Jantscher-Krenn ◽  
Carolin Marx ◽  
Lars Bode

Human milk oligosaccharides (HMO) are complex glycans that are highly abundant in human milk, but not in infant formula. Accumulating data, mostly from in vitro and animal studies, indicate that HMO benefit the breast-fed infant in multiple ways and in different target organs. In vitro incubation studies suggest that HMO can resist the low pH in the infant's stomach and enzymatic degradation in the small intestine and reach the colon in the same composition as in the mother's milk. The oligosaccharide composition in faeces of breast-fed infants is, however, very different from that in the mother's milk, raising questions on when, where and how HMO are metabolised between ingestion and excretion. To answer some of these questions, we established a pulse-chase model in neonatal rats and analysed HMO profiles to track their composition over time in five consecutive equal-length intestinal segments as well as in serum and urine. The relative abundance of individual HMO changed significantly within the first 2 h after feeding and already in the segments of the small intestine prior to reaching the colon. Only 3′-sialyllactose, the major oligosaccharide in rat milk, and hardly any other HMO appeared in the serum and the urine of HMO-fed rats, indicating a selective absorption of rat milk-specific oligosaccharides. The present results challenge the paradigm that HMO reach the colon and other target organs in the same composition as originally secreted with the mother's milk. The present results also raise questions on whether rats and other animals represent suitable models to study the effects of HMO.


2021 ◽  
Vol 12 ◽  
Author(s):  
Anaïs Rousseaux ◽  
Carole Brosseau ◽  
Sophie Le Gall ◽  
Hugues Piloquet ◽  
Sébastien Barbarot ◽  
...  

Breastmilk is known to be very important for infants because it provides nutrients and immunological compounds. Among these compounds, human milk oligosaccharides (HMOs) represent the third most important component of breastmilk after lipids and lactose. Several experiments demonstrated the beneficial effects of these components on the microbiota, the immune system and epithelial barriers, which are three major biological systems. Indeed, HMOs induce bacterial colonization in the intestinal tract, which is beneficial for health. The gut bacteria can act directly and indirectly on the immune system by stimulating innate immunity and controlling inflammatory reactions and by inducing an adaptive immune response and a tolerogenic environment. In parallel, HMOs directly strengthen the intestinal epithelial barrier, protecting the host against pathogens. Here, we review the molecular mechanisms of HMOs in these different compartments and highlight their potential use as new therapeutic agents, especially in allergy prevention.


Nutrients ◽  
2018 ◽  
Vol 10 (8) ◽  
pp. 1038 ◽  
Author(s):  
Julio Plaza-Díaz ◽  
Luis Fontana ◽  
Angel Gil

Maternal milk contains compounds that may affect newborn immunity. Among these are a group of oligosaccharides that are synthesized in the mammary gland from lactose; these oligosaccharides have been termed human milk oligosaccharides (HMOs). The amount of HMOs present in human milk is greater than the amount of protein. In fact, HMOs are the third-most abundant solid component in maternal milk after lactose and lipids, and are thus considered to be key components. The importance of HMOs may be explained by their inhibitory effects on the adhesion of microorganisms to the intestinal mucosa, the growth of pathogens through the production of bacteriocins and organic acids, and the expression of genes that are involved in inflammation. This review begins with short descriptions of the basic structures of HMOs and the gut immune system, continues with the beneficial effects of HMOs shown in cell and animal studies, and it ends with the observational and randomized controlled trials carried out in humans to date, with particular emphasis on their effect on immune system development. HMOs seem to protect breastfed infants against microbial infections. The protective effect has been found to be exerted through cell signaling and cell-to-cell recognition events, enrichment of the protective gut microbiota, the modulation of microbial adhesion, and the invasion of the infant intestinal mucosa. In addition, infants fed formula supplemented with selected HMOs exhibit a pattern of inflammatory cytokines closer to that of exclusively breastfed infants. Unfortunately, the positive effects found in preclinical studies have not been substantiated in the few randomized, double-blinded, multicenter, controlled trials that are available, perhaps partly because these studies focus on aspects other than the immune response (e.g., growth, tolerance, and stool microbiota).


2008 ◽  
Vol 101 (4) ◽  
pp. 482-486 ◽  
Author(s):  
Patrick Hong ◽  
Milady R. Ninonuevo ◽  
Benhur Lee ◽  
Carlito Lebrilla ◽  
Lars Bode

Breast-feeding is the predominant postnatal transmission route for HIV-1 infection in children. However, a majority of breast-fed infants do not become HIV-infected despite continuous exposure to the virus through their mothers' milk over many months. What protects some breast-fed infants from HIV-1 infection? HIV-1 entry across the infant's mucosal barrier is partially mediated through binding of the HIV-1 surface glycoprotein gp120 to dendritic cell-specific ICAM3-grabbing non-integrin (DC-SIGN) on human dendritic cells. Lewis antigen glycans, present in human milk, bind to DC-SIGN and inhibit HIV-1 transfer to CD4+T lymphocytes. Human milk contains a high amount of unbound, complex oligosaccharides (5–10 g/l) that carry one or more Lewis antigen glycans, and we hypothesized that they compete with gp120 for DC-SIGN binding. Here, we show in two independent assays that physiological concentrations of human milk oligosaccharides significantly reduce gp120 binding to DC-SIGN by more than 80 %. These results may provide an additional explanation for the inhibitory effects of human milk on HIV-1 mother-to-child-transmission. Identifying the specific milk oligosaccharides that interact with DC-SIGN may guide the development of glycan-based drugs that prevent transmission of HIV-1 and other pathogens that use DC-SIGN as an entry point. However, blocking DC-SIGN may be a two-edged sword.


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