scholarly journals Utilization efficiency of human milk oligosaccharides by human-associated Akkermansia is strain-dependent

2021 ◽  
Author(s):  
Estefani Luna ◽  
Shanthi G Parkar ◽  
Nina Kirmiz ◽  
Stephanie Hartel ◽  
Erik Hearn ◽  
...  
Keyword(s):  
Human Milk ◽  
Growth Yield ◽  
Intestinal Bacteria ◽  
Glycoside Hydrolases ◽  
Utilization Efficiency ◽  
Human Milk Oligosaccharides ◽  
Yield Strain ◽  
Metabolic Potential ◽  
Milk Oligosaccharides ◽  
Degrading Bacteria

Akkermansia muciniphila are mucin degrading bacteria found in the human gut and are often associated with positive human health. However, despite being detected as early as one month of age, little is known about the role of Akkermansia in the infant gut. Human milk oligosaccharides (HMOs) are abundant components of human milk and are structurally similar to the oligosaccharides that comprise mucin, the preferred growth substrate of human-associated Akkermansia. A limited subset of intestinal bacteria has been shown to grow well on HMOs and mucin. We therefore examined the ability of genomically diverse strains of Akkermansia to grow on HMOs. First, we screened 85 genomes representing the four known Akkermansia phylogroups to examine their metabolic potential to degrade HMOs. Furthermore, we examined the ability of representative isolates to grow on individual HMOs in a mucin background and analyzed the resulting metabolites. All Akkermansia genomes were equipped with an array of glycoside hydrolases associated with HMO-deconstruction. Representative strains were all able to grow on HMOs with varying efficiency and growth yield. Strain CSUN-19 belonging to the AmIV phylogroup, grew to the highest level in the presence of fucosylated and sialylated HMOs. This activity may be partially related to the increased copy numbers and/or the enzyme activities of the α-fucosidases, β-sialidases, and β-galactosidases. Utilization of HMOs by strains of Akkermansia suggests that ingestion of HMOs by an infant may enrich for these potentially beneficial bacteria. Further studies are required to realize this opportunity and deliver long-lasting metabolic benefits to the human host.

scholarly journals Fucosylated Human Milk Oligosaccharides and N-Glycans in the Milk of Chinese Mothers Regulate the Gut Microbiome of Their Breast-Fed Infants during Different Lactation Stages

mSystems ◽  
2018 ◽  
Vol 3 (6) ◽  
Author(s):  
Yaqiang Bai ◽  
Jia Tao ◽  
Jiaorui Zhou ◽  
Qingjie Fan ◽  
Man Liu ◽  
...  
Keyword(s):  
Gut Microbiota ◽  
Human Milk ◽  
Gut Microbiome ◽  
Longitudinal Research ◽  
Protein Glycosylation ◽  
Glycoside Hydrolases ◽  
Human Milk Oligosaccharides ◽  
Milk Oligosaccharides ◽  
Chinese Mothers ◽  
Breast Fed

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.

scholarly journals Synthesis of Human Milk Oligosaccharides: Protein Engineering Strategies for Improved Enzymatic Transglycosylation

Molecules ◽  
2019 ◽  
Vol 24 (11) ◽  
pp. 2033 ◽  
Author(s):  
Birgitte Zeuner ◽  
David Teze ◽  
Jan Muschiol ◽  
Anne S. Meyer
Keyword(s):  
Protein Engineering ◽  
Human Milk ◽  
Active Site ◽  
Enzymatic Synthesis ◽  
Spatial Arrangement ◽  
Glycoside Hydrolases ◽  
High Yield ◽  
Human Milk Oligosaccharides ◽  
Milk Oligosaccharides ◽  
Enzyme Active Site

Human milk oligosaccharides (HMOs) signify a unique group of oligosaccharides in breast milk, which is of major importance for infant health and development. The functional benefits of HMOs create an enormous impetus for biosynthetic production of HMOs for use as additives in infant formula and other products. HMO molecules can be synthesized chemically, via fermentation, and by enzymatic synthesis. This treatise discusses these different techniques, with particular focus on harnessing enzymes for controlled enzymatic synthesis of HMO molecules. In order to foster precise and high-yield enzymatic synthesis, several novel protein engineering approaches have been reported, mainly concerning changing glycoside hydrolases to catalyze relevant transglycosylations. The protein engineering strategies for these enzymes range from rationally modifying specific catalytic residues, over targeted subsite −1 mutations, to unique and novel transplantations of designed peptide sequences near the active site, so-called loop engineering. These strategies have proven useful to foster enhanced transglycosylation to promote different types of HMO synthesis reactions. The rationale of subsite −1 modification, acceptor binding site matching, and loop engineering, including changes that may alter the spatial arrangement of water in the enzyme active site region, may prove useful for novel enzyme-catalyzed carbohydrate design in general.

scholarly journals Reconstruction of the Bifidobacterial Pan-Secretome Reveals the Network of Extracellular Interactions between Bifidobacteria and the Infant Gut

2018 ◽  
Vol 84 (16) ◽  
Author(s):  
Gabriele Andrea Lugli ◽  
Walter Mancino ◽  
Christian Milani ◽  
Sabrina Duranti ◽  
Francesca Turroni ◽  
...  
Keyword(s):  
Human Milk ◽  
Protein Translocation ◽  
Bifidobacterium Longum ◽  
Extracellular Proteins ◽  
Glycoside Hydrolases ◽  
Secreted Proteins ◽  
Human Milk Oligosaccharides ◽  
Secretion Systems ◽  
Milk Oligosaccharides ◽  
Content Type

ABSTRACT The repertoire of secreted proteins decoded by a microorganism represents proteins released from or associated with the cell surface. In gut commensals, such as bifidobacteria, these proteins are perceived to be functionally relevant, as they regulate the interaction with the gut environment. In the current study, we screened the predicted proteome of over 300 bifidobacterial strains among the currently recognized bifidobacterial species to generate a comprehensive database encompassing bifidobacterial extracellular proteins. A glycobiome analysis of this predicted bifidobacterial secretome revealed that a correlation exists between particular bifidobacterial species and their capability to hydrolyze human milk oligosaccharides (HMOs) and intestinal glycoconjugates, such as mucin. Furthermore, an exploration of metatranscriptomic data sets of the infant gut microbiota allowed the evaluation of the expression of bifidobacterial genes encoding extracellular proteins, represented by ABC transporter substrate-binding proteins and glycoside hydrolases enzymes involved in the degradation of human milk oligosaccharides and mucin. Overall, this study provides insights into how bifidobacteria interact with their natural yet highly complex environment, the infant gut.IMPORTANCE The ecological success of bifidobacteria relies on the activity of extracellular proteins that are involved in the metabolism of nutrients and the interaction with the environment. To date, information on secreted proteins encoded by bifidobacteria is incomplete and just related to few species. In this study, we reconstructed the bifidobacterial pan-secretome, revealing extracellular proteins that modulate the interaction of bifidobacteria with their natural environment. Furthermore, a survey of the secretion systems between bifidobacterial genomes allowed the identification of a conserved Sec-dependent secretion machinery in all the analyzed genomes and the Tat protein translocation system in the chromosomes of 23 strains belonging to Bifidobacterium longum subsp. longum and Bifidobacterium aesculapii.

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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