WEDNESDAY, May 8, 2024 (HealthDay News) -- Systemic antibiotic exposure in the first year of life is associated with higher atopic dermatitis (AD) risk in a dose-response fashion, according to a study published online April 24 in the Journal of Allergy and Clinical Immunology.

Courtney Hoskinson, from the University of British Columbia in Vancouver, Canada, and colleagues examined the timing and specific factors mediating the relationship among systemic (oral or intravenous) antibiotic usage, the gut microbiome, and AD.

The researchers found that systemic antibiotics during the first year of life, as compared with later, were associated with AD risk (adjusted odds ratio, 1.81), with an increased number of antibiotic courses corresponding to a dose-response increased risk for AD (adjusted odds ratios, 1.67 and 2.16 for one and two or more courses, respectively). Microbiome alterations associated with both AD and systemic antibiotic usage fully mediate the effect of antibiotic usage on the development of AD. Among participants who would later develop AD, alterations in the one-year infant gut microbiome included increased Tyzzerella nexilis, increased monosaccharide utilization, and parallel decreased Bifidobacterium, Eubacterium spp., and fermentative pathways.

"Our findings indicate that early-life antibiotic usage, especially in the first year of life, modulates key gut microbiome components that may be used as markers to predict and possibly prevent the development of AD," the authors write.

Abstract/Full Text