Breastfed Babies Who Need Antibiotics Protected From Risk of Asthma, Suggests Study

Breastfed Babies Who Need Antibiotics Protected From Risk of Asthma, Suggests Study
(metamorworks/Shutterstock)
Marnie Cathcart
1/8/2023
Updated:
1/11/2023

A new study supported by BC Children’s Hospital suggests that breastfeeding can protect babies from the risk of developing asthma due to antibiotics use, as breast milk helps to keep the infant’s gut microbiome—the environment of bacteria and other microorganisms in the digestive tract—balanced.

The study, published in the journal Med on Jan. 4, found that children who were not breastfed and who required antibiotics in the first 12 months of life had three times the risk of developing asthma.

Asthma is the most common chronic, non-contagious childhood disease, affecting about 14 percent of children globally, the study said, adding that it is the leading reason for pediatric emergency room visits and can result in lifelong poor lung health.

A body of previous research suggests that a healthy microbiome early in life helps the immune system develop properly and prevents asthma, while antibiotic exposure in the first year of life elevates asthma risk, states the study.

A woman nurses her son outside an H&M store in Vancouver in August 2008. (The Canadian Press/Darryl Dyck)
A woman nurses her son outside an H&M store in Vancouver in August 2008. (The Canadian Press/Darryl Dyck)

The study said antibiotic exposure early in life is associated with widespread changes to the infant’s gut microbiome and results in enriched antibiotic-resistant genes months after treatment. Moreover, it depletes the infant’s digestive tract of beneficial bacteria and other microbes.

Asthma had “no such association in children who received antibiotics while breastfeeding,” said the study, because breastfeeding regulates and rebalances their gut microbiome to maintain healthy levels of key beneficial microbes.

Breastfeeding Beneficial

The study notes that breastfeeding has “long been recognized for its beneficial effect on newborn health” and that human milk is adapted to genetic, dietary, and environmental influences thus making it optimized and personalized for the breastfed infant.

“In addition to supporting infant physiology, breastfeeding is one of the most influential factors affecting infant gut microbiota development,” suggests the study, which was based on 2,521 children.

The children were part of the CHILD Cohort Study, the largest study in Canada tracking how genes and the environment interact to cause allergies, asthma, and other chronic diseases. CHILD stands for Canadian Healthy Infant Longitudinal Development.

Launched in 2008, the study recruited over 3,500 pregnant women, who gave birth between 2009 and 2012, and is following their children to school age and beyond.

Of the total 2,521 children considered in the breastfeeding analysis, 2,102 (83.4 percent) did not receive any antibiotics before their first birthday, 286 (11.3 percent) received antibiotics while being breastfed, and 133 (5.3 percent) received antibiotics without being breastfed in their first year of life.

Compared with those with no antibiotic exposure in the first year of life, the children who took antibiotics but were not breastfed had three-fold higher odds of developing asthma.

“When we directly compared children who were breastfed while taking antibiotics with those who were not, we identified significantly lower odds for asthma development ... when children were being breastfed at the time of antibiotic exposure,” stated the authors.

New research done out of BC Children's Hospital suggests that children who are breastfed while on antibiotics have a lower risk of developing asthma compared to those not breastfed.  (Marina Demidiuk/ Shutterstock)
New research done out of BC Children's Hospital suggests that children who are breastfed while on antibiotics have a lower risk of developing asthma compared to those not breastfed.  (Marina Demidiuk/ Shutterstock)

‘Clear Protection’

The study noted that while some infants do require antibiotics, early exposure to antibiotics is linked to disruption in the infant gut microbiome.
The Harvard T.H. Chan School of Public Health describes the microbiome inside the gut as consisting of “trillions of microorganisms (also called microbiota or microbes) of thousands of different species,” including bacteria, fungi, parasites, and viruses.
“In a healthy person, these ‘bugs’ coexist peacefully, with the largest numbers found in the small and large intestines but also throughout the body,” according to Harvard.

“The microbiome is even labelled a supporting organ because it plays so many key roles in promoting the smooth daily operations of the human body.”

Microbes in the microbiome are helpful as long as they remain in balance. Infectious illnesses, viruses, poor diet, or prolonged use of antibiotics or medications that disrupt bacteria can throw the microbiome out of balance and lead to illness, Harvard says.

“A person is first exposed to microorganisms as an infant, during delivery in the birth canal and through the mother’s breast milk. Exactly which microorganisms the infant is exposed to depends solely on the species found in the mother. Later on, environmental exposures and diet can change one’s microbiome to be either beneficial to health or place one at greater risk for disease,” according to Harvard.

The CHILD study suggests that breastfeeding, with its known benefits, has many more beneficial effects yet to be discovered.

“We identified clear protection from asthma risk when children are breastfed at the time of antibiotics exposure,” concluded the researchers.