Protective bacteria in the infant gut have resourceful way of helping babies break down breast milk

by Danielle Gutierrez

A research team at the University of California, Davis, has found that important and resourceful bacteria in the baby microbiome can ferret out nourishment from a previously unknown source, possibly helping at-risk infants break down components of breast milk.

Breast milk is amazingly intricate, providing all of the necessary to sustain and strengthen infants in the first months of life. Moreover, this of nutrition provides protection from infections, allergies and many other illnesses.

Breast milk also promotes the growth of protective bacteria in an infant's intestine. Because breast milk contains glycans (complex sugars) that infants cannot breakdown, it promotes the growth a specific type of bacteria, called bifidobacteria, that can process these glycans. While it is known that bifidobacteria avail themselves of the free glycans in breast milk, it was not known whether these bacteria could also obtain glycans that were linked to proteins. Such proteins are called glycoproteins, and they are abundant in breast milk.

The research team led by David A. Mills at the UC-Davis investigated the ability of bifidobacteria to remove glycans from milk glycoproteins. Their work was recently published in the journal Molecular & Cellular Proteomics.

Mills' group found that specific strains of bifidobacteria possessed enzymes capable of removing glycan groups from glycoproteins, enabling them to use these glycans as an additional food source. Surprisingly, one of the enzymes, EndoBI-1, was able to remove any type of N-linked glycan (glycans attached to proteins by the amino acid asparagine). This is unique among enzymes of this type and may provide a growth advantage for bifidobacteria in the infant because the glycoproteins in have complex glycans attached.

Mills explains that the ability of EndBI-1 to remove a variety of complex N-linked glycans combined with its unusual heat stability make "this potentially a very useful tool in both food processing and proteomics/pharmaceutical research."

The team's work suggests that bifidobacteria do not primarily feed on the glycans from milk glycoproteins. However, the study did show that under the proper conditions bidfidobacteria can grow when -linked glycans are the only energy source.

"One obvious goal of this research is to find ways to translate the benefits provided by milk and to at risk populations such as premature infants, malnourished children, among many others," Mills says.

More information: "Endo-β-N-acetylglucosaminidases from infant-gut associated bifidobacteria release complex N-glycans from human milk glycoproteins" by Daniel Garrido, Charles Nwosu, Santiago Ruiz-Moyano, Danielle Aldredge, J. Bruce German, Carlito B. Lebrilla and David A. Mills.

Related Stories

Carbohydrate acts as tumor suppressor

Jul 06, 2009

Scientists at Burnham Institute for Medical Research (Burnham) have discovered that specialized complex sugar molecules (glycans) that anchor cells into place act as tumor suppressors in breast and prostate cancers. These ...

Recommended for you

Stem cells faulty in Duchenne muscular dystrophy

14 hours ago

Like human patients, mice with a form of Duchenne muscular dystrophy undergo progressive muscle degeneration and accumulate connective tissue as they age. Now, researchers at the Stanford University School of Medicine have ...

Here's how the prion protein protects us

19 hours ago

The cellular prion protein (PrPC) has the ability to protect the brain's neurons. Although scientists have known about this protective physiological function for some time, they were lacking detailed knowledge ...

Regulation of maternal miRNAs in early embryos revealed

20 hours ago

The Center for RNA Research at the Institute for Basic Science (IBS) has succeeded in revealing, for the first time, the mechanism of how miRNAs, which control gene expression, are regulated in the early embryonic stage.

User comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.