Early-life gut microbial colonization is crucial for immune system development, but the efficacy of probiotic interventions during pregnancy or infancy in preventing allergic rhinitis (AR) and atopic sensitization (AS) remains unclear. This systematic review synthesized evidence from randomized controlled trials (RCTs) assessing probiotics for AR and AS prevention.

Seven English and Chinese databases were systematically searched up to February 13, 2025. Eligible studies were RCTs with clearly defined probiotic interventions and specified AR or AS outcomes. Risk of bias was assessed using the Cochrane tool. Odds ratios (ORs) with 95% confidence intervals (CIs) were pooled using fixed-effects models.

Fourteen RCTs involving 5886 children were included. Probiotics did not significantly reduce the odds of AR at any age (≤ 1 year: ORp = 0.73, 95% CI = 0.46–1.15, P = 0.17; > 1 year: ORp = 0.95, 95% CI = 0.83–1.09, P = 0.46). However, probiotics significantly reduced AS odds in children over 1 year (ORp = 0.87, 95% CI = 0.76–0.99, P = 0.04). Subgroup analyses revealed greater reductions in AS odds for postnatal interventions initiated after 6 months of age (ORp = 0.82, 95% CI = 0.68–0.99, P = 0.04) and for combined prenatal-postnatal supplementation (ORp = 0.85, 95% CI = 0.74–0.98, P = 0.03). Probiotics were also associated with transient increases in the abundance of targeted gut microbial strains.

Probiotics during pregnancy and/or infancy may reduce AS odds in children over 1 year and correlate with age-related changes in gut microbial composition but failed to reduce AR odds at any age.

Allergic rhinitis

Atopic sensitization

Probiotics supplementation

Gut microbiota

Meta-analysis

© 2025 The Author(s). Published by Elsevier Inc. on behalf of World Allergy Organization.