Prebiotics may play a role in avoiding food allergies

Findings from a trial undertaken by researchers at The Kids Research Institute Australia show that among mothers who received antibiotics during labour, those who supplemented with a prebiotic during pregnancy did not have an increased risk of their baby developing food allergy. 

In contrast, children born to mothers who received antibiotics but did not take prebiotics were more than five times more likely to develop a food allergy.

Summer Walker, lead author and research assistant at The Kids, said about one in four Australian mothers received antibiotic treatment during pregnancy.

“Most commonly antibiotics is given in labour to women with Group B Streptococcus (GBS) which can cause sepsis and be quite life-threatening for babies. Mums will normally get swabbed in pregnancy and if they have the bacteria then they usually get antibiotics once they go into hospital after their waters break,” she said.

“They might also have antibiotics during labour if they've had GBS in a previous pregnancy because they're at higher risk of having it again, or for other things such as prolonged rupture of membranes or high temperatures - they're all risk factors of GBS.”

Lead author and Research Assistant at The Kids Research Institute Australia, Summer Walker.

Ms Walker said there had been increasing concern regarding the potential link between antibiotics and food allergies, with maternal antibiotic use during pregnancy shown to be associated with a higher risk of child eczema and food allergies.

“We know that prebiotics promote the growth of healthy gut bacteria, while antibiotics disrupt the gut microbiome by reducing diversity and potentially leading to a gut microbiome imbalance.

“During pregnancy this can potentially result in long-term child health effects,” she said.

Mrs Walker stressed that antibiotics were often essential during labour and saved lives, so they should always be used when needed.

The trial

As part of the SYMBA trial in Western Australia, researchers followed 652 pregnant women and their babies – the majority from ORIGINS, Australia’s largest longitudinal birth cohort of its kind – from mid-pregnancy until one year of age.

Women consumed either a prebiotic or a placebo supplement from mid-pregnancy until their baby was six months old.

All babies had a family history of allergic disease and more than 80% of mothers and 20% of babies received antibiotics during the study intervention period.

“Among mothers who did not take prebiotics, antibiotic exposure during labour was associated with a more than five‑fold increase in food allergy risk in babies,” Ms Walker said.

“Our findings suggest a particularly vulnerable period around birth where antibiotic use may negatively influence a baby’s developing immune system.”

Previous research has often grouped together antibiotics given during labour and those given for caesarean births but this study looked at these separately.

“Antibiotic levels peak in the umbilical cord within 30 minutes and remain bactericidal for several hours, regardless of labour duration,” Ms Walker said.

Consequently, that means antibiotics given during labour may have a greater impact on the infant microbiome due to longer foetal exposure.

“This research is an important first step and opens the door to exploring whether prebiotics could also help protect against other child health conditions linked to antibiotics,” Ms Walker said.

“For now, it’s best for women to follow existing dietary advice and speak with their healthcare provider before starting supplements.

“The good news is that many healthy diets, such as the Mediterranean diet, are rich in prebiotic containing foods such as garlic, leeks, onions, asparagus and legumes.”

The research has been published in the international journal Allergy.