David Sela, a nutrition scientist at the University of Massachusetts Amherst, has received a five-year $1.69 million grant from the National Institutes of Health (NIH) to study how nitrogen in breast milk is used by beneficial microbes in the gut of infants. to potentially play an important role in the nutrition and development of children.
The new experiments, funded by the NIH’s National Institute of Child Health and Human Development, may also provide molecular targets to diagnose and intervene to improve the efficiency of nitrogen metabolism through the microbiome in infants and possibly adults.
It was once thought that the nutrients and bioactive compounds in breast milk were transferred directly to the infant in a linear fashion, explains Sela, an associate professor of nutritional science and director of the Fergus M. Clydesdale Center for Foods for Health and Wellness.
Now there is significant evidence that breast milk directs the early establishment of the microbiome through molecules, such as oligosaccharides, that modulate specific microbial populations to influence infant health and well-being.”
David Sela, nutrition scientist, University of Massachusetts Amherst
In the Sela Lab, Sela and his team study Bifidobacterium infantis, a beneficial bacteria that colonizes the guts of babies. “This particular microbe has a close relationship with the baby and uses breast milk products, including those that the babies don’t digest, but would otherwise pass through their bodies,” Sela says.
Sela’s early work identified that some of the microbe’s genes are related to urea hydrolysis, which got Sela thinking. “Urea is a waste product in humans. Why do we see so much urea in breast milk? We add two and two together and I hypothesized that this microbe actually has a different connection to breast milk: it uses this waste product as a nitrogen source.”
This urea nitrogen storage is known to be important in ruminants and may be an important feature of the interactions between the infant and the microbiome. “It could be critical for infants in general or in certain feeding contexts,” Sela says.
Those questions and hypotheses will guide and inform Sela’s new research, which will include experiments to understand both the details and the big picture.
“We want to understand the system by which nitrogen and metabolism are intertwined between the mother’s diet, mother’s milk and the baby’s needs, and how the microbes contribute to the baby’s nitrogen metabolism,” says Sela. “We want to mechanistically characterize what goes on inside the microbes themselves. We try to reduce the system to its components and then paint the bigger picture once we understand the smaller aspects of it,” Sela says.
In short, if researchers can confirm that urea nitrogen storage is important for infant nutrition and development, they will focus on potential interventions if it would benefit infant outcomes. Those interventions may include maternal or baby nutritional supplements, including probiotics, and address other aspects of the mother’s lifestyle.
“These are the open questions that we hope to solve in the coming years,” says Sela.
University of Massachusetts Amherst