Background: Accumulating evidence suggests that the gut microbiota shapes developmental processes within the immune system. Early life antibiotic use is one factor which may contribute to immune dysfunction and the recent surge in allergies by virtue of its effects on gut microbiota. Objective and methods: As a first step towards determining whether a relationship exists between perinatal antibiotic induced changes in the gut microbiota and the later development of a peanut allergy, we exposed newborn mice to either the broad-spectrum antibiotic vancomycin or to a vehicle for 6 weeks and then used a novel murine model of peanut allergy. Results: Early-life treatment with vancomycin resulted in a significant shift in the gut microbiota community characterized by a reduction in the abundance of firmicutes and preponderance of inflammatory proteobacteria. Mice with an antibiotic-altered microbiota, showed a localized allergic-like response characterized by ear swelling and scratching following intra-dermal peanut antigen challenge. Likewise, circulating IgE levels were increased in antibiotic-treated mice, but no evidence of a systemic allergic or anaphylactic-like response was observed. Importantly, we utilized the naturally occurring pro-inflammatory cytokine, tumor necrosis factor-α (TNF-α), rather than the more commonly used cholera toxin, as an adjuvant together with the peanut antigen. Conclusion: Our data suggest that early antibiotic exposure promotes a shift in the gut microbiota community that may in turn, influence how mice later respond to a TNF-α + antigen challenge. However, further studies verifying the capacity of microbiota restoration to protect against allergic responses will be needed to confirm a causal role of antibiotic-induced microbiota variations in promoting allergic disease phenotypes.

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Allergy, Asthma and Clinical Immunology
Department of Neuroscience

Boutin, R.C.T. (Rozlyn C. T.), Dwyer, Z. (Zach), Farmer, K. (Kyle), Rudyk, C. (Chris), Forbes, M.R. (Mark R.), & Hayley, S. (2018). Perinatal antibiotic exposure alters composition of murine gut microbiota and may influence later responses to peanut antigen. Allergy, Asthma and Clinical Immunology, 14(1). doi:10.1186/s13223-018-0263-8