Early antibiotic exposure shows limited link to pediatric T1D risk

A large meta-analysis of observational studies found no clear association between prenatal antibiotic exposure and the development of type 1 diabetes (T1D) in children, while early-life antibiotic use was associated with only a modest increase in risk.¹ The findings were published in Diabetes, Obesity, and Metabolism following a systematic review of studies conducted across high-income countries.¹

Given rising global incidence of pediatric T1D and increasing antibiotic use in early life, the question of whether microbiome disruption contributes to autoimmune disease risk remains clinically relevant.² However, the current analysis suggests that any relationship is small and potentially confounded.¹

“An improved understanding of associations between antibiotic use and T1D is important as it may guide the development of interventions to halt the worrying increase in T1D observed in many parts of the world,” wrote investigators.

Meta-analysis evaluates prenatal and early childhood exposure

Investigators conducted a systematic review and meta-analysis following PRISMA guidelines, searching major databases through June 2025. A total of 20 studies met inclusion criteria, including 11 cohort studies and 9 case-control studies published between 2000 and 2025. All studies were conducted in high-income countries and were largely rated as high quality based on Newcastle-Ottawa Scale assessments.

For prenatal exposure, 8 studies encompassing more than 1.5 million participants were included. These studies evaluated maternal antibiotic use during pregnancy and subsequent T1D diagnosis in offspring. The pooled effect estimate showed no significant association between prenatal antibiotic exposure and T1D risk, with a relative risk of 1.05. Subgroup analyses suggested a small association in cohort studies but not in case-control studies.

For postnatal exposure, 15 studies including more than 4.6 million children examined antibiotic use during early childhood, typically within the first 1 to 2 years of life. The pooled estimate showed a modest but statistically significant association with T1D risk, with a relative risk of 1.07. However, heterogeneity across studies was moderate, and effect sizes varied widely.

Modest associations influenced by dose and context

Several subgroup analyses explored potential modifiers of risk. Broad-spectrum antibiotics were associated with a slightly greater risk compared with narrow-spectrum agents, with a pooled estimate of 1.13. No consistent associations were observed for specific antibiotic classes, including penicillins, macrolides, or cephalosporins.

Dose-response patterns were inconsistent. Greater cumulative exposure, such as 5 or more courses, was associated with a small increase in risk, with pooled estimates ranging from 1.11 to 1.14. However, most individual studies did not demonstrate statistically significant findings.

Sibling-matched analyses in several studies, which help account for shared genetic and environmental factors, found no association between early-life antibiotic use and T1D. This suggests that residual confounding may explain some of the observed associations in conventional analyses.

Some studies also identified potential effect modification by mode of delivery. Increased risk associated with early antibiotic exposure was more pronounced in children delivered by cesarean section, although findings were not consistent across all studies.

Clinical interpretation remains cautious

T1D is one of the most common autoimmune diseases in children, with rising incidence worldwide. The gut microbiome has been proposed as a potential mediator linking environmental exposures to immune dysregulation. Antibiotics may alter microbial composition during critical developmental windows, providing biological plausibility for an association.

However, the current findings suggest that antibiotic exposure alone is unlikely to be a major driver of T1D risk. The modest effect sizes, lack of consistency across studies, and attenuation in sibling analyses all point toward potential confounding by indication, infection burden, or other early-life exposures.

From a clinical perspective, these results do not support changes in current antibiotic prescribing practices when clinically indicated. Judicious antibiotic use remains important, but concerns about T1D risk should not override appropriate treatment decisions.

“Future research should more clearly disentangle the role of infections, address reverse causation, examine potential interactions with mode of obstetric delivery, and clarify the independent effects of broad- versus narrow-spectrum and specific antibiotic classes,” wrote investigators.

References

1. Ram S, Corbin M, Mannetje A, Douwes J, Kvalsvig A, Eng A. Antibiotic exposure in early life and risk of type 1 diabetes: a meta-analysis. Diabetes, Obesity, and Metabolism. 2026. doi:10.1111/dom.70636
2. Klein EY, Van Boeckel TP, Martinez EM, et al. Global increase and geographic convergence in antibiotic consumption between 2000 and 2015. Proc Natl Acad Sci U S A. 2018;115(15):E3463-E3470. doi:10.1073/pnas.1717295115