Antibiotic-associated gut microbiome dysbiosis increases atopic dermatitis risk

Published: April 24, 2024

Atopic dermatitis is a chronic inflammatory skin disease with many potential driving factors. In their study, published in The Journal of Allergy and Clinical Immunology (JACI), Hoskinson & Medeleanu et al. identified a link between antibiotics (intravenous or oral) given to children in their first year of life and the development of atopic dermatitis by age 5 years. The first year of life is a particularly sensitive and formative time for not only the immune system, but the gut microbiome as well. Bacterial populations within the gut play a large part in shaping the integrity of the gut and educating immune cell subsets, such as T-regulatory cells that are essential for immune tolerance.

The study included clinical data from 2,484 CHILD Study participants, of whom 516 were treated with antibiotics within the first year and 365 were diagnosed with atopic dermatitis. The authors identified a significantly increased risk of atopic dermatitis at age 5 when participants were treated with antibiotics in early life. Given the link between antibiotics and the gut microbiome, the authors then compared the 1-year gut microbiomes of children treated with early antibiotics to those not, as well as those with atopic dermatitis at age 5 and those not using shotgun metagenomic sequencing and structural equation modeling.

In summary, the authors found that antibiotics (the most common of which was amoxicillin) taken during the first year of life, as compared to later, is associated with an increased risk of developing atopic dermatitis during childhood. Further, this risk increases with additional courses of antibiotics. They also found that the use of antibiotics in the first year and the diagnosis of atopic dermatitis at age 5 were associated with significant shifts and alterations in bacterial species and function compared to participants not treated with antibiotics. Specifically, species within the keystone genus Bifidobacterium and fermentative capacity (implying the production of immune regulating short-chain fatty acids) were notably reduced in participants treated with antibiotics and in those diagnosed with atopic dermatitis.

This study provides insight into the long-term impact of antibiotics and identifies potential bacteria to target or rescue with future biotherapeutics. It also provides actionable and clinically relevant insight that calls for responsible antibiotics stewardship as a strategy for preventing atopic dermatitis and perhaps other allergic outcomes.

The Journal of Allergy and Clinical Immunology (JACI) is an official scientific journal of the AAAAI, and is the most-cited journal in the field of allergy and clinical immunology.

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