The long-debated link between early antibiotic exposure and type 1 diabetes mellitus (T1DM) remains uncertain. A meta-analysis published in Frontiers in Endocrinology found no overall association between antibiotic exposure during pregnancy or after birth and later T1DM in children or adolescents, although a higher risk signal emerged in those born by cesarean section after postnatal exposure.

The study systematically searched PubMed, Web of Science, EMBASE, and Science Direct from database inception through October 2025 for cohort studies evaluating early-life antibiotic exposure and T1DM risk. Seven eligible studies involving approximately 7.4 million participants were included. Pooled hazard ratios (HRs) with 95% confidence intervals (CIs) were used to compare exposed and unexposed groups.

Maternal antibiotic exposure during pregnancy was not significantly associated with T1DM risk in offspring (HR, 1.06; 95% CI, 0.98-1.15; P=0.146). Antibiotic exposure after birth also showed no significant overall association (HR, 1.03; 95% CI, 0.95-1.11; P=0.491). Additional subgroup analyses examining sibling comparisons, sex, timing of exposure, frequency of exposure, antibiotic class, and antibacterial spectrum similarly found no significant differences between exposed and unexposed groups.

However, among children born by cesarean section, antibiotic exposure after birth was associated with higher T1DM incidence compared with unexposed controls (HR, 1.62; 95% CI, 1.31-2.01; P<0.001). These findings suggest early-life antibiotic exposure was not linked to T1DM overall, but birth-related factors may modify risk and warrant further investigation.