Probiotics reduce nasal and eye symptom scores in children with allergic rhinitis

BACKGROUND: Allergic rhinitis (AR) is a prevalent chronic inflammatory disorder in children, often undiagnosed and associated with reduced quality of life and risk of comorbidities such as asthma. Probiotics have been found to be potential modulators of immune responses in allergic conditions. This systematic review and meta-analysis evaluated the efficacy of probiotics compared with placebo in the management of pediatric AR. METHODS: Searches were conducted in accordance with a pre-registered protocol using MEDLINE (PubMed), the Web of Science, Scopus, and Embase through April 8, 2025. Randomized controlled trials (RCTs) of children aged < 18 years that compared probiotics, prebiotics, or synbiotics with a placebo were considered for inclusion. Outcomes of interest included clinical and laboratory parameters. Random-effects models with Hedges' g were used; heterogeneity was assessed via I. RESULTS: Fourteen RCTs involving 1,739 children were included. Meta-analysis revealed a significant reduction in nasal symptom scores (SMD = -1.40; 95% CI: -2.26 to -0.54; I = 91.3%) and eye symptom scores (SMD = -3.59; 95% CI: -5.84 to -1.33; I = 94.3%). Quality of life (RQLQ) was also significantly improved (SMD = -2.98; 95% CI: -4.85 to -1.12; I = 95.7%). Among laboratory markers, a small but significant increase in serum eosinophils was observed (SMD = 0.29; 95% CI: 0.06 to 0.52; I = 0%). CONCLUSION: Probiotics were associated with improvements in nasal and ocular symptoms and quality of life in children with AR; however, these findings should be interpreted with caution due to substantial heterogeneity across studies. Probiotics may have a potential role as an adjunctive therapy, but further high-quality, standardized trials are needed. PROSPERO registration code: CRD420250654461 on 24 February 2025. What is Known • Probiotics have been investigated as adjunctive therapy for pediatric allergic rhinitis because of their potential immunomodulatory effects. • Previous studies and meta-analyses have reported inconsistent findings regarding the clinical and immunological effects of probiotics in allergic rhinitis. What is New •This meta-analysis demonstrated significant improvements in nasal symptoms, ocular symptoms, and quality of life in children with allergic rhinitis receiving probiotics versus placebo. • Probiotic supplementation showed no consistent beneficial effects on immunological markers, while substantial heterogeneity remained across studies.