Kids prescribed antibiotics but not fed breast milk at triple risk of asthma: study

A Canadian study suggests that children who were not breastfed while taking antibiotics in the first year of life were three times more likely to develop asthma because they lacked specific protective sugars in their breast milk.

dr Stuart Turvey, a lead researcher, said antibiotics like amoxicillin are commonly prescribed to treat a variety of infections in young children, but the drugs have also been linked to disrupting the development of a healthy gut microbiome.

“What we’ve known for a while is that babies who were given antibiotics early in life are at higher risk of developing asthma in school age and beyond, but no one knew why,” said Turvey, a pediatrician at BC Children’s Hospital.

The study, published Wednesday in the journal Med, found that sugars in breast milk, which make up about 20 percent of indigestible carbohydrates, encourage the growth of B. infantis bacteria to help create other bacteria to train the immune system and prevent the development of asthma and allergies.

The researchers also said they identified the breast milk sugar that provides this protection, which could potentially be used to supplement the formula for infants who need antibiotics but for whom breastfeeding is not an option.

“Children are born with virtually no bacteria,” Turvey said. “Then these communities (of bacteria) start to form, with pioneer species helping the others to establish themselves. So timing is important,” he said, when people are prescribed antibiotics that “confuse” children’s immune systems in the first few months of life.

A total of 2,521 children in Vancouver, Edmonton, Winnipeg and Toronto took part in the study. It showed that 17 percent of the children received antibiotics in the first year of life.

Three groups of children were compared – those who did not receive antibiotics, those who received them while breastfeeding and those who received them without breastfeeding.

When a subset of 1,338 infants was three months old, researchers collected a soiled diaper to test for bowel movements. A year later, another diaper was taken for a stool sample from the same children, Turvey said, adding that the cost of the relatively new technology prevented all of the children’s samples from being tested.

“We took the fecal samples and then did metagenomics, a type of genetic sequencing, to identify all the bacteria based on the DNA that was there. This (B. infantis) was a really strong signal,” he said.

At the age of five, all children were screened for asthma. Those who did not receive breast milk but were prescribed antibiotics were three times more likely to develop the disease.

“The children who received the antibiotics while breastfeeding were no more at risk than the children who did not receive antibiotics,” Turvey said.

“One important thing was that any breastfeeding was protective. So it wasn’t just exclusive breastfeeding without any other form of nutrition.”

Asthma is a top reason for children visiting emergency rooms and doctor’s offices, often while missing school, he said, adding that despite the results, amoxicillin is a potentially life-saving drug for very young children.

The study results could stimulate clinical trials to determine whether the natural sugars in breast milk can be used to supplement the formula for the benefit of people who are unable to breastfeed their infants, Turvey said. Chemists could create synthetic versions of the sugars similar to those already in formulas, he added.

“More knowledge of the protective might inform this process.”

Ailbhe Smyth, a volunteer at a Vancouver chapter of La Leche League who supports breastfeeding mothers, said those struggling with an often-challenging experience like it’s been for them don’t see the results as another cause for guilt should be “a perfect parent”.

Fewer public health clinics offered lactation specialist support even before the pandemic, and some women are opting for private counselors to avoid long waiting lists, Smyth said.

“But that is still an obstacle. Some people just don’t have the extra money for it,” she said, adding, “I think the support has to come not just from the healthcare system, but from society in general.”

This report from The Canadian Press was first published on January 5, 2023.

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Canadian Press health reporting is supported by a partnership with the Canadian Medical Association. CP is solely responsible for this content.