The microbe Prevotella copri is found in the gut of most people living traditional hunter-gatherer lifestyles, but is far less prevalent in people living in Western countries.
The study — a collaboration between Barwon Health, Deakin University and the Murdoch Children’s Research Institute — involved data collected from more than 1,000 mothers and their babies in Victoria’s Barwon region between 2010 and 2013.
The researchers took faecal samples from the women when they were 36 weeks pregnant, and their infants at one, six and 12 months old.
They identified 61 children with an allergy to food including eggs, peanuts and cow’s milk.
A DNA analysis showed babies born to women carrying the bacteria had a substantially reduced risk of developing a food allergy.
“Only one mother with more than a minute trace of Prevotella copri had a baby that developed a food allergy,” study co-author Peter Vuillermin said.
Associate Professor Vuillermin, from Deakin University, said scientists eventually hoped to develop a probiotic to help mothers boost their baby’s immune system.
“We hope that it gives us a clue towards developing a supplement that we could offer women during pregnancy that would reduce the baby’s risk of allergic disease,” he said.
One in 10 babies develop a food allergy in Australia, which is the highest reported rate in the world.
Bacteria like Prevotella copri produce molecules that can cross the placenta and stimulate a baby’s developing immune system.
The study has been published in the journal Nature Communications.