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

• DOI: 10.1074/mcp.m116.060665
• Publication Date: 2016-07-20T03:15:22Z
• Authors: Jasmine C.C. Davis; Sarah M. Totten; Julie O. Huang; Sadaf Nagshbandi; Nina Kirmiz; Daniel A. Garrido; Zachery T. Lewis; Lauren D. Wu; Jennifer T. Smilo...; J. Bruce German; David A. Mills; Carlito B. Lebrilla
• Keywords: Bifidobacterium longum; Digestion; Prebiotic; Oligosaccharide

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