Breastmilk may ward off bacterial infections in babies

Protective sugars found in breastmilk can help protect babies against bacterial infections, researchers have found. Group B strep bacteria, whose common host are pregnant women, remain the leading cause of severe infections in newborns worldwide, which often leads to sepsis or pneumonia, and in severe cases death, because they do not have fully developed defence mechanisms.

The study showed that sugars can act as anti-biofilm agents, which is the first example of carbohydrates in human milk having this function.
"This is the first example of generalised, antimicrobial activity on the part of the carbohydrates in human milk," said Steven Townsend, assistant professor at the Vanderbilt University in Tennessee, US.

"One of the remarkable properties of these compounds is that they are clearly non-toxic, unlike most antibiotics," Townsend added. Nearly 10 years ago, researchers had found that pregnant women play host to group B strep bacteria and the pathogen can be transmitted to infants through breastfeeding.

But because most babies do not become infected with group B strep, they wanted to see if some women's breast milk contained protective compounds that specifically fight that bacteria. In the new study, the team members are testing more than a dozen additional milk samples to see if breastmilk sugars are effective.

So far, two samples have shown activity against both bacteria and biofilms; two just worked against bacteria but not biofilms; and four helped fight biofilm formation but not bacteria. Six were relatively inactive against both. The results, presented at the 254th National Meeting and Exposition of the American Chemical Society (ACS) in Washington, showed that these sugars, sensitise the target bacteria and then they kill them.

Preliminary data also suggest that some mothers produce milk sugars that make the bacteria more susceptible to common antibiotics, including penicillin and erythromycin. If these results bear out through future studies, these sugars could potentially become a part of an antibacterial treatment for infants or adults. They could also help reduce our dependence on some common antibiotics, Townsend added.