The rise of drug-resistant bacteria is a growing concern in the world of medical science and beyond. These bugs are evolving to outfox even our very best medicines, presenting a real and emerging danger to humans in every corner of the globe. A new study has explored how drug-resistant bacteria develop in newborns in particular, and how a mother's breastmilk might help fend them off.

Driven in large part by overprescription, experts worry that the evolution of antibiotic-resistant bacteria, or superbugs, threaten to return the world to the dark ages of medicine. One UK government report predicts that if no action is taken, superbugs could kill up to 10 million people a year by 2050.

But the numbers surrounding the impacts of antibiotic-resistant bacteria on newborns, who have weaker immune systems, are already astounding. According to the World Health Organization, more than 200,000 newborns die every year from infections that simply don't respond to existing drugs. Data taken from larger hospitals, where there is more scope for the development of resistance, indicates that around 40 percent of infections in newborns don't respond to standard treatments.

Superbugs can be found all over the place, from our skin, to food, to our bellies. To explore the role that breastfeeding might play in how they evolve in infants, microbiologists from Finland's University of Helsinki analyzed breastmilk and faecel matter from 16 infant-mother pairings. This is obviously a small sample size, but in decoding the bacterial DNA and genes in these samples, the team wound up with what it calls the largest DNA sequence library of breastmilk ever created.

"Such studies were practically impossible only a few years ago." explains Katariina Pärnänen, lead author on the study. "For instance, the laboratory techniques required for processing DNA into sequence-able form have advanced to the extent that the amount of source material needed is today a thousand times smaller than, say, five years ago."

From their analysis, the scientists were able to tally up the amount of antibiotic resistance genes (ARGs), which give rise to antibiotic-resistant bacteria. The team found, for the first time, that these genes are present in breastmilk in significant numbers, and that these are likely passed onto infants through breastfeeding.

This would seem to suggest that breastfeeding is a bad idea, at least so far as superbugs are concerned. But the analysis also revealed how sugars in the milk power the development of beneficial bacteria in the infant's stomach. These sugars are vital in helping the good bacteria get the upper hand on the bad.

So much so, the team found that infants breastfed for at least six months had less drug-resistant bacteria in their gut overall than babies breastfed for shorter periods or not at all.

"We have already known that breastfeeding is all in all healthy and good for the baby, but we now discovered that it also reduces the number of bacteria resistant to antibiotics," says Pärnänen.

Another interesting detail to emerge from the work pertains to the use of antibiotics during delivery. These might be administered before or during labor for a whole host of reasons to avoid infection, and the researchers say, albeit cautiously, the results indicate that they also boost the number of resistant bacteria in the baby's gut.

"We cannot advise that mothers should not be given antibiotics during delivery," says Pärnänen. "The consequences of infection for both mother and infant are potentially serious. What we can state is our findings, and physicians can use them to consider whether practices should be changed or not."

The team's research was published in the journal Nature Communications.