New technique developed by a team of University of California at Davis (UCD) and Agilent scientists enables rapid, detailed analysis of the composition of a group of bioactive molecules in breast milk
Oligosaccharides (OGs) comprise the third-largest solid component of breast milk, following lactose and lipids.
More than 200 OGs have been identified in recent decades, but, until now, there has been no way to measure their presence in an individual sample in a single test or run.
Measuring and determining the role of OGs in breast milk has until now been hampered both by OGs' diversity and by inherent limitations of the research tools used, all requiring long run periods and huge sample quantities.
In a study recently published in the online version of the Journal of Agricultural and Food Chemistry, the UCD-Agilent group detailed its successful use of two Agilent analytical tools to identify presence of OGs in samples from five women in single runs.
Agilent's novel glycan chip, developed at Agilent Laboratories to perform high-resolution separation of complex OG mixtures: this is an application-specific version of Agilent's high-performance liquid chromatography (HPLC) chip, introduced last year.
Agilent's time-of-flight mass spectrometer (TOF MS), used to characterise each OG variation by accurately determining its mass at the molecular level, featuring two parts per million precision.
"The unique HPLC-chip/Tof combination has enabled exciting new results and a more complete understanding of complex oligosaccharides moieties," says UC Davis chemistry professor Carlito Lebrilla, lead author of the paper.
"This has significantly helped advance our team's OG research and will undoubtedly have extensions to other glycan structures, with applications in such important areas as biotherapeutics".
The structures of the individual OGs were determined by matrix-assisted laser desorption/ionization mass spectrometry (Maldi MS).
Large variations were observed in the total numbers and abundances of OGs, with the total number per individual varying from 33 to 124.
Only a few OGs were common to all subjects.
Multidisciplinary engineers and scientists at Agilent Laboratories, Agilent's central research organisation, fuelled the innovations that make this new measurement technique possible.
Labs and Agilent businesses collaborate closely to provide innovative solutions to customers by understanding continually evolving market conditions, customer needs and technology goals.
"Researchers have long wondered why OG is present in breast milk, as its exact role in infant development has yet to be identified," explains co-author Rudi Grimm, worldwide proteomics and metabolomics market development manager with Agilent's life sciences and chemical analysis (LSCA) group.
"A recent hypothesis suggests that they could be determining factors in the development of intestinal bacteria and mucosal immune system.
"Our team's newly developed technique paves the way for further research into oligosaccharide function in human development".
For decades, breast milk has been recognised as the ideal food for newborns because its composition is adapted to the nutritional needs of each baby, generally containing appropriate amounts of carbohydrates, proteins, fats, digestive enzymes, minerals, vitamins, hormones and antibodies.
Its two main components are lactose and lipids, including cholesterol, fatty acids and triglycerides; also present are important proteins, including alpha-lactalbumin and whey.
OGs have evolved to be the third most abundant component in human milk, even though they have no direct nutritive value to the infant.
Research co-authors are Milady Ninonuevo, Youmie Park, Jinhua Zhang, Robert Ward, Brian Clowers, Bruce German, Samara Freeman and Carlito Lebrilla of UC Davis; Kevin Killeen and Hongfeng Yin of Agilent Labs; and Rudi Grimm of Agilent Technologies LSCA.
The research was supported in part by the California Dairy Research Foundation, the National Institutes of Health, the Charge Study and a UC Discovery grant.
