Objective Whether prenatal or postnatal exposure to antibiotics is associated with an increased risk of coeliac disease (CD) is unclear. We systematically reviewed studies on the association between early life antibiotic exposure and the risk of CD or CD autoimmunity.

Design Systematic review of observational studies.

Data sources The PubMed and Embase databases were searched up to December 2018, with no language restrictions. Additional references were obtained from reviewed articles.

Eligibility criteria for selecting studies Cohort, cross-sectional and case–control studies that assessed the association between prenatal and/or postnatal antibiotic exposure and the odds of developing CD (as defined by authors of the original studies) or CD autoimmunity were eligible for inclusion.

Results Six studies were included. In two large cohort studies that focused on prenatal antibiotic exposure, no association with the risk of CD was found (adjusted OR=1.16; 95% CI 0.94 to 1.43 and adjusted HR=1.33; 95% CI 0.69 to 2.56) in the Norwegian and Swedish cohorts, respectively. In three studies that evaluated the association of postnatal antibiotic exposure with the risk of CD, the results were contradictory, with only the Italian cohort study reporting a significant positive association (adjusted incidence rate ratio=1.24; 95% CI 1.07 to 1.43). A large, multicentre cohort study that evaluated the association between postnatal antibiotic exposure and CD autoimmunity in human leukocyte antigen (HLA)-positive subjects found no association.

Conclusions We found no evidence of an association between prenatal or postnatal antibiotic exposure and CD.