Creation of a milk oligosaccharide database, MilkOligoDB, reveals common structural motifs and extensive diversity across mammals

Authors: DURHAM, SIERRA - University Of California, Davis; WEI, ZHE - University Of California, Davis; Lemay, Danielle; LANGE, MATTHEW - International Center Cooperative Agricultural Research; BARILE, DANIELA - University Of California, Davis

Submitted to: Scientific Reports
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/12/2023
Publication Date: 6/26/2023
Citation: Durham, S.D., Wei, Z., Lemay, D.G., Lange, M., Barile, D. 2023. Creation of a milk oligosaccharide database, MilkOligoDB, reveals common structural motifs and extensive diversity across mammals. Scientific Reports. 13. Article 10345. https://doi.org/10.1038/s41598-023-36866-y.
DOI: https://doi.org/10.1038/s41598-023-36866-y

Interpretive Summary: A major component of human milk—oligosaccharides—is not digested by the infant, but by the infant’s gut bacteria. These milk oligosaccharides (oligos) have other health benefits as well, such as protection of the infant from pathogens. All mammals have some types of oligos, but the reports span 50 years with different types of descriptions. In this work, we harmonized reports from 157 publications into a standardized format and built a database, called MilkOligoDB, that contains 869 unique oligo structures from 75 mammalian species. While common structures of oligos are shared within groups of mammals, there are many variations. Three key features that define human milk oligos are shared only with the Asian elephant. However, animals like cows, goats, and pigs do generate a diverse set of oligosaccharides that may be valuable for human supplementation.

Technical Abstract: The carbohydrate fraction of most mammalian milks contains a variety of oligosaccharides that encompass a range of structures and monosaccharide compositions. Human milk oligosaccharides have received considerable recent attention due to their biological roles contributing to the establishment and maintenance of beneficial gut microbiota, prevention of pathogen binding to the intestinal epithelium, immunomodulation, and brain development in the neonate. However, a major challenge to understand the biology of milk oligosaccharides across mammals is that reports span 50 years of publications with different types of description of the structures. In the present study, reports of milk oligosaccharides in the literature were identified and harmonized into a standardized format to create a comprehensive, machine-readable database of milk oligosaccharides across mammalian species. The resulting database, MilkOligoDB, includes 869 unique oligosaccharide structures in the milk of 75 different species harvested from 157 publications. Common structural motifs emerge within Mammalian orders such as fucosylated or non-fucosylated, acidic or neutral, type 1 core dominant or type 2 core dominant, etc. and in the overall structure as branching or linear and with varying degrees of polymerization. Three key features define human milk oligosaccharides—high fucosylation, low Neu5Gc, and mostly core 1 structures. Of the other 74 species studies, only the Asian elephant shares these features. However, agriculturally important animals do generate a diverse set of oligosaccharides that may be valuable for human supplementation.