Breast not best as cow's milk 'provides protective properties for babies'
Breast milk has long been touted as the best for protecting a baby's health, but cow's milk also offers some protective properties, researchers have discovered.
Mother's milk guides the development of bacteria in a baby's intestines, nourishing a very specific population of "good" microbes that, in turn, provides nourishment and protects the child.
But now scientists from the University of California have identified the compound in the milk that supplies this nourishment, and have shown that it can be obtained from cow's milk.
This work could result in cow's milk being used to provide that compound as a prebiotic for infants.
Mother's milk co-evolved over millions of years with mammals and their beneficial gut bacteria .
Professor David Mills said: "It is the only food that co-evolved with humans to make us healthy.
"Mother's milk guides the development of [newborns'] gut microbiota, nourishing a very specific bacterial population that, in turn, provides nourishment and protects the child.
"Now we have identified the compound in the milk that supplies this nourishment, and have shown that it can be obtained from cow's milk."
Previous studies by Prof Mills had shown that a type of protein in milk known as glycoproteins were the source of that nourishment, while a type of bacterium found in babies' intestines - B infantis - produced an enzyme that could process the nutrient.
In the new study, Prof Mills identified the sugars resulting from that process - oligosaccharides - as the food source for B infantis.
His team showed the enzyme could break down glycoproteins not only from mother's milk, but also from cow's milk, releasing the oligosaccharides.
The released sugars turned out to be a highly productive growth medium for B infantis, according to Prof Mills.
All that suggests that getting the bioactive oligosaccharides into infant formula could improve it.
Prof Mills said: "The amazing thing to me is how selective these released oligosaccharides are as a substrate for growth."
The study was published in the journal 'Applied and Environmental Microbiology'.