Dataset Information

Identification of Oligosaccharides in Feces of Breast-fed Infants and Their Correlation with the Gut Microbial Community.

ABSTRACT: Glycans in breast milk are abundant and found as either free oligosaccharides or conjugated to proteins and lipids. Free human milk oligosaccharides (HMOs) function as prebiotics by stimulating the growth of beneficial bacteria while preventing the binding of harmful bacteria to intestinal epithelial cells. Bacteria have adapted to the glycan-rich environment of the gut by developing enzymes that catabolize glycans. The decrease in HMOs and the increase in glycan digestion products give indications of the active enzymes in the microbial population. In this study, we quantitated the disappearance of intact HMOs and characterized the glycan digestion products in the gut that are produced by the action of microbial enzymes on HMOs and glycoconjugates from breast milk. Oligosaccharides from fecal samples of exclusively breast-fed infants were extracted and profiled using nanoLC-MS. Intact HMOs were found in the fecal samples, additionally, other oligosaccharides were found corresponding to degraded HMOs and non-HMO based compounds. The latter compounds were fragments of N-glycans released through the cleavage of the linkage to the asparagine residue and through cleavage of the chitobiose core of the N-glycan. Marker gene sequencing of the fecal samples revealed bifidobacteria as the dominant inhabitants of the infant gastrointestinal tracts. A glycosidase from Bifidobacterium longum subsp. longum was then expressed to digest HMOs in vitro, which showed that the digested oligosaccharides in feces corresponded to the action of glycosidases on HMOs. Similar expression of endoglycosidases also showed that N-glycans were released by bacterial enzymes. Although bifidobacteria may dominate the gut, it is possible that specific minority species are also responsible for the major products observed in feces. Nonetheless, the enzymatic activity correlated well with the known glycosidases in the respective bacteria, suggesting a direct relationship between microbial abundances and catabolic activity.

SUBMITTER: Davis JC

PROVIDER: S-EPMC5013312 | biostudies-literature | 2016 Sep

REPOSITORIES: biostudies-literature

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Publications

Identification of Oligosaccharides in Feces of Breast-fed Infants and Their Correlation with the Gut Microbial Community.

Davis Jasmine C C JC Totten Sarah M SM Huang Julie O JO Nagshbandi Sadaf S Kirmiz Nina N Garrido Daniel A DA Lewis Zachery T ZT Wu Lauren D LD Smilowitz Jennifer T JT German J Bruce JB Mills David A DA Lebrilla Carlito B CB

Molecular & cellular proteomics : MCP 20160719 9

Glycans in breast milk are abundant and found as either free oligosaccharides or conjugated to proteins and lipids. Free human milk oligosaccharides (HMOs) function as prebiotics by stimulating the growth of beneficial bacteria while preventing the binding of harmful bacteria to intestinal epithelial cells. Bacteria have adapted to the glycan-rich environment of the gut by developing enzymes that catabolize glycans. The decrease in HMOs and the increase in glycan digestion products give indicati ...[more]

PMID: 27435585

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Project description:BACKGROUND:Mother's own milk (MOM) is protective against gut microbiota alterations associated with necrotizing enterocolitis (NEC) and feeding intolerance among preterm infants. It is unclear whether this benefit is preserved with donor milk (DM) feeding. OBJECTIVE:We aimed to compare microbiota development, growth, and feeding tolerance in very-low-birth-weight (VLBW) infants fed an exclusively human milk diet of primarily MOM or DM. METHODS:One hundred and twenty-five VLBW infants born at Texas Children's Hospital were enrolled and grouped into cohorts based on percentage of MOM and DM in enteral feeds. Feeds were fortified with DM-derived fortifier per unit protocol. Weekly stool samples were collected for 6 wk for microbiota analysis [16S ribosomal RNA (rRNA) sequencing]. A research nurse obtained weekly anthropometrics. Clinical outcomes were compared via Wilcoxon's rank-sum test and Fisher's exact test, as well as multivariate analysis. RESULTS:The DM cohort (n = 43) received on average 14% mothers' milk compared with 91% for the MOM cohort (n = 74). Diversity of gut microbiota across all time points (n = 546) combined was increased in MOM infants (P < 0.001). By 4 and 6 wk of life, microbiota in MOM infants contained increased abundance of Bifidobacterium (P = 0.02) and Bacteroides (P = 0.04), whereas DM-fed infants had increased abundance of Staphylococcus (P = 0.02). MOM-fed infants experienced a 60% reduction in feeding intolerance (P = 0.03 by multivariate analysis) compared with DM-fed infants. MOM-fed infants had greater weight gain than DM-fed infants. CONCLUSIONS:Compared with DM-fed infants, MOM-fed infants have increased gut microbial community diversity at the phylum and genus levels by 4 and 6 wk of life, as well as better feeding tolerance. MOM-fed infants had superior growth. The incidence of NEC and other gastrointestinal morbidity is low among VLBW infants fed an exclusively human milk diet including DM-derived fortifier. This trial was registered at clinicaltrials.gov as NCT02573779.

Project description: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.

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Dataset Information

Identification of Oligosaccharides in Feces of Breast-fed Infants and Their Correlation with the Gut Microbial Community.

Publications

Identification of Oligosaccharides in Feces of Breast-fed Infants and Their Correlation with the Gut Microbial Community.

Similar Datasets

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