Gestational diabetes mellitus affects the fucosylation and sialylation levels of N/O-glycans in human milk glycoproteins

Label-Free Liquid Chromatography–Mass Spectrometry Quantitation of Relative N- and O-Glycan Concentrations in Human Milk in Japan

“…These results are consistent with those reported in previous studies [17,21,33], emphasizing the significantly higher levels of fucosylation and sialylation in both Nand O-glycans in human milk. However, our results deviate from the lower proportions documented by Wang et al in healthy individuals [27]. This discrepancy suggests the possibility of variation due to lactation period, ethnicity, and regional factors and the need for a nuanced understanding of human milk glycosylation.…”

“…More than 70% of the detected N/O-glycans were sialylated, fucosylated, or both sialylated and fucosylated (Figure 1). The total numbers of N/O-glycans detected via label-free LC-MS were comparable with those reported previously [21,23,24,27]. We did not consider sulfated O-glycans in this study, although a previous study had reported them [24].…”

“…The structural diversity of N/O-glycans is presumed to vary among individuals, similar to the variation seen among HMOs, but the details are unknown. Human milk has been analyzed for the Nglycans [15,[17][18][19][20][21][22][23], O-glycans [24], or both N/O-glycans [25][26][27] present. Although human milk was provided by 4-30 women for these reports, no information concerning individual differences or the distribution of N/O-glycans was available because the individual milk samples were pooled before analysis.…”

Comparative Site-Specific O-Glycosylation Analysis of the Milk Fat Globule Membrane Proteome in Donkey Colostrum and Mature Milk

“…As shown in Figure A,B, both DC and DM MFGM glycoprotein O -glycans were predominantly mucin-type core structures, with 38.56% core-2 glycans, 25.77% core-4 glycans, 19.67% core-3 glycans, and 14.16% core-1 glycans in DC and 28.89% core-2 glycans, 25.1% core-4 glycans, 23.39% core-1 glycans, and 21.14% core-3 glycans in DM. The highest proportion of core-2 O -glycans was found in donkey MFGM proteins, which is consistent with previous studies on human milk O -glycomics, which identified the highest proportion of core-2 glycoforms and laterally reflected the similarity between human and donkey milk in terms of O -glycan core structural dimensions. , Mucin-type O -glycans, as a major type of O -glycosylation, exist mainly in core-1, core-2, core-3, and core-4 core structures, which not only serve as important mediators of host–microbe–pathogen interactions in the intestine but can also be degraded as a nutrient source, serve as binding sites to promote intestinal colonization, and act as soluble decoy receptors to bind and sequester pathogens and their toxins . Notably, we identified Tn antigen O -glycans for the first time in donkey MFGM proteins, and their abundance decreased slightly with the development of lactation (Figure A,B).…”

Alterations of milk oligosaccharides in mothers with gestational diabetes mellitus impede colonization of beneficial bacteria and development of RORγt + Treg cell-mediated immune tolerance in neonates

“… 3–5 It alters the glycosylation pattern of N-glycans in human milk, and thus affects the gut microbiota composition of offspring. 36 , 37 However, little is known about the effects of altered HMOs of GDM in mothers on the gut microbiota and development of immune tolerance in their offspring. In the present study, we systematically characterized changes in HMO patterns in Chinese GDM mothers during various stages of lactation and evaluated the possible effects on gut microbiota and immune responses in their infants.…”