Antibiotics Before Age 2 Associated With Childhood Health Issues

Summary: Researchers have identified an association between antibiotics administered to children aged two and under, and an increased risk of ongoing conditions ranging from ADHD to obesity. Children exposed to numerous courses of antibiotics as toddlers were more likely to be diagnosed with continuous conditions later in childhood. The study speculates that while antibiotics may only have a transient effect on the developing microbiome, this may have an impact on long-term illness.

Source: Mayo Clinic

In a retrospective case study, Mayo Clinic researchers have found that antibiotics administered to children younger than 2 are associated with several ongoing illnesses or conditions, ranging from allergies to obesity. The findings appear in Mayo Clinic Proceedings.

Using health record data from the Rochester Epidemiology Project, a population-based research collaboration in Minnesota and Wisconsin, researchers analyzed data from over 14,500 children. About 70% of the children had received at least one treatment with antibiotics for illness before age 2. Children receiving multiple antibiotic treatments were more likely to have multiple illnesses or conditions later in childhood.

Types and frequency of illness varied depending on age, type of medication, dose and number of doses. There also were some differences between boys and girls. Conditions associated with early use of antibiotics included asthma, allergic rhinitis, weight issues and obesity, food allergies, attention deficit hyperactivity disorder, celiac disease, and atopic dermatitis. The authors speculate that even though antibiotics may only transiently affect the microbiome, the collection of microbes in the body, this may have long-term health consequences.

“We want to emphasize that this study shows association ― not causation ― of these conditions,” says Nathan LeBrasseur, Ph.D., a researcher at Mayo Clinic’s Robert and Arlene Kogod Center on Aging and the study’s senior author. “These findings offer the opportunity to target future research to determine more reliable and safer approaches to timing, dosing and types of antibiotics for children in this age group.”

While recent data show an increase in some of the childhood conditions involved in the study, experts are not sure why. Other than the issue of multidrug resistance, antibiotics have been presumed safe by most pediatricians.

This shows a toddler sleeping
The authors speculate that even though antibiotics may only transiently affect the microbiome, the collection of microbes in the body, this may have long-term health consequences. Image is in the public domain

Researchers also say the ultimate goal is to provide practical guidelines for physicians on the safest way to use antibiotics early in life.

Other coauthors of the study are Zaira Aversa, M.D., Ph.D., first author; Elizabeth Atkinson; Marissa Schafer, Ph.D.; Regan Theiler, M.D., Ph.D.; and Walter Rocca, M.D. ― all of Mayo Clinic ― and Martin Blaser, M.D., of Rutgers University.

Funding: The study was supported by the Pritzker Foundation, Leonard and Mary Lou Hoeft Fund in Healthy Aging and Independent Living Research, Rochester Epidemiology Project, C&D Fund, and Transatlantic Networks of Excellence of the Leducq Foundation.

The Rochester Epidemiology Project has been supported by the National Institutes of Health since its inception more than 50 years ago.

About this neurodevelopment research news

Source: Mayo Clinic
Contact: Bob Nellis – Mayo Clinic
Image: The image is in the public domain

Original Research: Open access.
Association of Infant Antibiotic Exposure With Childhood Health Outcomes” by Nathan LeBrasseur et al. Mayo Clinic Proceedings


Association of Infant Antibiotic Exposure With Childhood Health Outcomes


To investigate the extent to which antibiotic exposure in the first 2 years of life is associated with the risk of immunological, metabolic, and neurobehavioral health conditions with childhood onset.

Patients and Methods

In this population-based cohort study, we identified all children born in Olmsted County, Minnesota, between January 1, 2003, and December 31, 2011, through the Rochester Epidemiology Project medical records-linkage system. Demographic characteristics, antibiotic prescriptions, and diagnostic codes through June 30, 2017, were retrieved using the Rochester Epidemiology Project infrastructure. Time-to-event analysis was performed to assess the impact of antibiotic exposure on the risk of several adverse health conditions.


This study included 14,572 children (7026 girls and 7546 boys), of whom 70% (10,220) received at least 1 antibiotic prescription during the first 2 years of life. Early antibiotic exposure was associated with an increased risk of childhood-onset asthma, allergic rhinitis, atopic dermatitis, celiac disease, overweight, obesity, and attention deficit hyperactivity disorder (hazard ratios ranging from 1.20 to 2.89; P<.05 for all). The associations were influenced by the number, type, and timing of antibiotic exposure. Moreover, children exposed to antibiotics had a higher probability of having combinations of conditions, particularly when given multiple prescriptions.


The present study finds significant associations between early life antibiotic exposure and several distinct health conditions with childhood onset. Additional research is warranted to establish practical guidelines to optimize the benefit and minimize the risk of antibiotics in children.

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