Synthesis and biological relevance of N-acetylglucosamine-containing oligosaccharides

2007 ◽  
Vol 79 (12) ◽  
pp. 2229-2242 ◽  
Author(s):  
El Sayed H. El Ashry ◽  
Mohamed R. E. Aly
Keyword(s):  
Human Milk ◽  
Biological Significance ◽  
Structural Diversity ◽  
Human Milk Oligosaccharides ◽  
Milk Oligosaccharides ◽  
Biological Relevance ◽  
Glycosidic Bonds ◽  
Synthetic Approaches

The structural diversity as well as the biological significance of N-acetylglucosamine-containing glycans are exemplified. The problem of forming the respective glycosidic bonds of synthetic targets is addressed. Special emphasis has been given to human milk oligosaccharides (HMOs), in view of their biological relevance, and synthetic approaches of selected examples are reported.

scholarly journals Human Milk Oligosaccharides Influence Neonatal Mucosal and Systemic Immunity

2016 ◽  
Vol 69 (Suppl. 2) ◽  
pp. 41-51 ◽  
Author(s):  
Sharon M. Donovan ◽  
Sarah S. Comstock
Keyword(s):  
Human Milk ◽  
Infant Formula ◽  
Bovine Milk ◽  
Complex Mixture ◽  
Structural Diversity ◽  
Host Cells ◽  
Human Milk Oligosaccharides ◽  
Milk Oligosaccharides ◽  
Immune Development ◽  
Breastfed Infants

The immune system of the infant is functionally immature and naïve. Human milk contains bioactive proteins, lipids, and carbohydrates that protect the newborn and stimulate innate and adaptive immune development. This review will focus on the role human milk oligosaccharides (HMO) play in neonatal gastrointestinal and systemic immune development and function. For the past decade, intense research has been directed at defining the complexity of oligosaccharides in the milk of many species and is beginning to delineate their diverse functions. These studies have shown that human milk contains a higher concentration as well as a greater structural diversity and degree of fucosylation than the milk oligosaccharides in other species, particularly bovine milk from which many infant formulae are produced. The commercial availability of large quantities of certain HMO has furthered our understanding of the functions of specific HMO, which include protecting the infant from pathogenic infections, facilitating the establishment of the gut microbiota, promoting intestinal development, and stimulating immune maturation. Many of these actions are exerted through carbohydrate-carbohydrate interactions with pathogens or host cells. Two HMOs, 2′-fucosyllactose (2′FL) and lacto-N-neotetraose (LNnT), have recently been added to infant formula. Although this is a first step in narrowing the compositional gap between human milk and infant formula, it is unclear whether 1 or 2 HMO will recapitulate the complexity of actions exerted by the complex mixture of HMO ingested by breastfed infants. Thus, as more HMO become commercially available, either isolated from bovine milk or chemically or microbially synthesized, it is anticipated that more oligosaccharides will be added to infant formula either alone or in combination with other prebiotics.

scholarly journals Human Milk Oligosaccharides: The Journey Ahead

2019 ◽  
Vol 2019 ◽  
pp. 1-8 ◽  
Author(s):  
Chandan Ray ◽  
Joshi A. Kerketta ◽  
Subhash Rao ◽  
Snehal Patel ◽  
Shantanu Dutt ◽  
...  
Keyword(s):  
Breast Milk ◽  
Human Milk ◽  
Current Knowledge ◽  
Biological Fluid ◽  
Structural Diversity ◽  
Host Cells ◽  
Future Research ◽  
Human Milk Oligosaccharides ◽  
Milk Oligosaccharides ◽  
Signalling Molecules

Breast milk is a complex biological fluid that is rich in nutrients and bioactive agents that support the healthy growth and development of the newborns. Human milk oligosaccharides (HMOs) are unconjugated glycans that constitute an important component of the protection conferred by breast milk on the neonate. HMOs may act locally on the neonatal intestine by acting as signalling molecules and directly interacting with the host cells. Although fucosylated and sialylated HMOs have little nutritional value, they exert important prebiotic as well as immunomodulatory effects on the infant gut. However, there is heterogeneity in the quantity and quality of HMOs in breast milk produced by mothers under influence of the genetic and environmental factors. This review encompasses the salient aspects of HMOs such as composition, function, structural diversity, and functional impact on the growth and survival of newborns. In this review, the current knowledge on HMOs is contextualised to discuss the gaps in scientific understanding and the avenues for future research.

scholarly journals Human Milk Oligosaccharides Exhibit Biofilm Eradication Activity Against Matured Biofilms Formed by Different Pathogen Species

2022 ◽  
Vol 12 ◽  
Author(s):  
Sylwia Jarzynka ◽  
Riccardo Spott ◽  
Tinatini Tchatchiashvili ◽  
Nico Ueberschaar ◽  
Mark Grevsen Martinet ◽  
...  
Keyword(s):  
Human Milk ◽  
Pathogenic Bacteria ◽  
Biological Significance ◽  
Burkholderia Cenocepacia ◽  
Respiratory Pathogens ◽  
Human Milk Oligosaccharides ◽  
Group B Streptococci ◽  
Milk Oligosaccharides ◽  
Gram Positive ◽  
Group B

Human milk oligosaccharides (HMOs) have been shown to exhibit plenty of benefits for infants, such as prebiotic activity shaping the gut microbiota and immunomodulatory and anti-inflammatory activity. For some pathogenic bacteria, antimicrobial activity has been proved, but most studies focus on group B streptococci. In the present study, we investigated the antimicrobial and antibiofilm activities of the total and fractionated HMOs from pooled human milk against four common human pathogenic Gram-negative species (Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Burkholderia cenocepacia) and three Gram-positive species (Staphylococcus aureus, Enterococcus faecium, and Enterococcus faecalis). The activity of HMOs against enterococci and B. cenocepacia are addressed here for the first time. We showed that HMOs exhibit a predominant activity against the Gram-positive species, with E. faecalis being the most sensitive to the HMOs, both in planktonic bacteria and in biofilms. In further tests, we could exclude fucosyllactose as the antibacterial component. The biological significance of these findings may lie in the prevention of skin infections of the mother’s breast as a consequence of breastfeeding-induced skin laceration and/or protection of the infants’ nasopharynx and lung from respiratory pathogens such as staphylococci.

Beneficial effects of human milk oligosaccharides on gut microbiota

2014 ◽  
Vol 5 (3) ◽  
pp. 273-283 ◽  
Author(s):  
S. Musilova ◽  
V. Rada ◽  
E. Vlkova ◽  
V. Bunesova
Keyword(s):  
Gut Microbiota ◽  
Human Milk ◽  
Pathogenic Bacteria ◽  
Structural Diversity ◽  
Human Milk Oligosaccharides ◽  
High Concentration ◽  
Milk Oligosaccharides ◽  
Beneficial Effects ◽  
Specific Effects ◽  
The Relationship

Human milk is the gold standard for nourishment of early infants because it contains a number of bioactive components, such as human milk oligosaccharides (HMOs). The high concentration and structural diversity of HMOs are unique to humans. HMOs are a group of complex and diverse glycans that are resistant to gastrointestinal digestion and reach the infant colon as the first prebiotics. N-acetyl-glucosamine containing oligosaccharides were first identified 50 years ago as the ‘bifidus factor’, a selective growth substrate for intestinal bifidobacteria, thus providing a conceptual basis for HMO-specific bifidogenic activity. Bifidobacterial species are the main utilisers of HMOs in the gastrointestinal tract and represent the dominant microbiota of breast-fed infants, and they may play an important role in maintaining the general health of newborn children. Oligosaccharides are also known to directly interact with the surface of pathogenic bacteria, and various oligosaccharides in milk are believed to inhibit the binding of pathogens and toxins to host cell receptors. Furthermore, HMOs are thought to contribute to the development of infant intestine and brain. Oligosaccharides currently added to infant formula are structurally different from the oligosaccharides naturally occurring in human milk and, therefore, they are unlikely to mimic some of the structure-specific effects. In this review, we describe how HMOs can modulate gut microbiota. This article summarises information up to date about the relationship between the intestinal microbiota and HMOs, and other possible indirect effects of HMOs on intestinal environment.

scholarly journals Effects of Different Human Milk Oligosaccharides on Growth of Bifidobacteria in Monoculture and Co-culture With Faecalibacterium prausnitzii

2020 ◽  
Vol 11 ◽  
Author(s):  
Lianghui Cheng ◽  
Mensiena B. G. Kiewiet ◽  
Madelon J. Logtenberg ◽  
Andre Groeneveld ◽  
Arjen Nauta ◽  
...  
Keyword(s):  
Human Milk ◽  
Human Milk Oligosaccharides ◽  
Milk Oligosaccharides ◽  
Faecalibacterium Prausnitzii

scholarly journals Regulation of hBD-2, hBD-3, hCAP18/LL37, and Proinflammatory Cytokine Secretion by Human Milk Oligosaccharides in an Organotypic Oral Mucosal Model

Pathogens ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 739
Author(s):  
Ulvi K. Gürsoy ◽  
Krista Salli ◽  
Eva Söderling ◽  
Mervi Gürsoy ◽  
Johanna Hirvonen ◽  
...  
Keyword(s):  
Human Milk ◽  
Expression Profiles ◽  
Three Dimensional ◽  
Human Milk Oligosaccharides ◽  
Proinflammatory Response ◽  
Milk Oligosaccharides ◽  
Culture Model ◽  
Gingival Cells ◽  
Mucosal Secretion ◽  
Immunomodulatory Potential

Human milk oligosaccharides (HMOs), the third largest solid fraction in human milk, can modulate inflammation through Toll-like receptor signaling, but little is known about their immunomodulatory potential in the oral cavity. In this study, we determined whether the HMOs 2’-fucosyllactose (2’-FL) and 3-fucosyllactose (3-FL) regulate human-beta defensin (hBD)-2 and -3, cathelicidin (hCAP18/LL-37), and cytokine responses in human gingival cells using a three-dimensional oral mucosal culture model. The model was incubated with 0.1% or 1% 2’-FL and 3-FL, alone and in combination, for 5 or 24 h, and hBD-2, hBD-3, and hCAP18/LL-37 were analyzed by immunohistochemistry. The expression profiles of interleukin (IL)-1, IL-1RA, IL-8, and monocyte chemoattractant protein (MCP)-1 were determined by LUMINEX immunoassay. The combination of 1% 2’-FL and 1% 3-FL, and 1% 3-FL alone, for 24 h upregulated hBD-2 protein expression significantly (p < 0.001 and p = 0.016, respectively). No changes in the other antimicrobial peptides or proinflammatory cytokines were observed. Thus, 3-FL, alone and in combination with 2´-FL, stimulates oral mucosal secretion of hBD-2, without effecting a proinflammatory response when studied in an oral mucosal culture model.

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