Repeated antibiotic exposure in early childhood may disrupt the developing gut microbiome and increase the risk of later inflammatory bowel disease (IBD), with the strongest association observed for Crohn’s disease, according to a recent study.

The incidence of childhood-onset IBD continues to rise in many countries, prompting growing interest in determining factors that may contribute to disease development.

Because the gut microbiome plays a central role in intestinal health and immune system maturation, research has increasingly focused on whether early-life antibiotic exposure may disrupt microbial development and influence future IBD risk.

Published in the journal Inflammatory Bowel Diseases, a new systematic review and meta-analysis sought to provide an updated assessment of the association between childhood antibiotic use and subsequent IBD development.

The study also investigated whether the relationship varied between Crohn’s disease and ulcerative colitis and considered if an underlying susceptibility to infection could explain any observed association.

Impact of early antibiotic exposure on IBD risk

A literature search of the MEDLINE and EMBASE databases to December 2024 identified 10 eligible studies, of which eight were used in the primary meta-analysis. This included 2,783 cases of childhood-onset IBD.

Additional disease-specific studies were included for Crohn’s disease and ulcerative colitis. All studies were deemed to have good methodological quality.

The primary outcome was the association between childhood antibiotic exposure from birth to 17 years and the subsequent development of IBD.

Compared with no antibiotic exposure, childhood antibiotic use was associated with a 42% increased risk of IBD overall.

Antibiotic exposure was associated with a 59% increase in the risk of Crohn’s disease, whereas the association with ulcerative colitis was more modest but still significant at 23%. Study heterogeneity was low to moderate, and there was no evidence of publication bias, the authors said.

Two studies reported stronger associations with antibiotic exposure in the first year of life than with exposure in later childhood. In addition, all studies reporting a positive overall association identified a dose–response relationship, with repeated antibiotic courses associated with greater risk than single courses.

Only one study directly adjusted for the frequency of childhood infections, but this had little impact on the association between antibiotic exposure and later IBD risk. Nevertheless, the authors cautioned that confounding by indication could not be excluded.

Limitations and further research

The review had several other limitations, with the included studies varying in their definitions of exposure, adjustment strategies and age ranges for antibiotic exposure. Information on the reasons for antibiotic prescribing was also generally unavailable, limiting the assessment of potential confounding.

While the findings do not prove causality, the authors argued that they support a link between childhood antibiotic exposure and later IBD development, especially Crohn’s disease. They highlighted the crucial need for careful antibiotic use in early childhood – a key period for gut microbiome development.

The authors also advocated that future research should explore how antibiotic-associated disruption of the microbiome contributes to disease risk and whether interventions such as probiotics, dietary modification or other microbiome-targeted strategies can mitigate potential long-term effects.

Reference
Størdal K et al. Systematic review and meta-analysis of childhood exposure to antibiotics and the subsequent risk of IBD. Inflamm Bowel Dis 2026;32:990–7.