Adjuvant probiotic therapy for accelerating oral immunotherapy in children with food allergy: a systematic review and meta-analysis protocol

Background Oral immunotherapy (OIT) for pediatric food allergy requires 6–12 months to achieve sustained unresponsiveness (SU), with variable patient adherence. Probiotic adjuvants may modulate immune responses and accelerate OIT efficacy, but existing meta-analyses focus predominantly on safety outcomes. This systematic review will evaluate probiotic efficacy in accelerating OIT treatment timelines and improving clinical outcomes. Methods This protocol follows the Preferred Reporting Items for Systematic Review and Meta-Analysis Protocols (PRISMA-P) 2015 guidelines and is registered with Prospero. We will search PubMed, Embase, Cochrane CENTRAL, and Scopus from January 1, 2010 to December 1, 2025, plus clinical trial registries and conference proceedings. Only randomized controlled trials (RCTs) comparing OIT plus probiotics versus OIT alone/placebo in children (0–18 years) with IgE-mediated food allergy will be included. Eligibility criteria: physician-diagnosed food allergy confirmed by skin prick test and/or specific IgE; probiotic strain, dosage, and timing explicitly reported; minimum 3-month follow-up. This protocol follows PRISMA-P guidelines and was registered on December 5, 2025. Primary outcome: Rate of sustained unresponsiveness (SU) achievement, reported as risk ratio (RR). Secondary outcomes: Time to maintenance dose (weeks), desensitization rate, immunomodulatory biomarkers (specific IgE, IgG4, IgE/IgG4 ratio), adverse events, and quality of life. Two independent reviewers will screen studies, extract data, and assess risk of bias using RoB-2. Meta-analysis will employ fixed-effects models (I² < 50%) or random-effects models (I² ≥ 50%). Sensitivity analyses will exclude high-risk studies and studies requiring SD imputation. Publication bias will be assessed via funnel plots and Egger’s test (≥ 10 studies). Certainty of evidence will be graded using GRADE. Synthesis is planned for March 2026. Discussion This review will provide evidence-based guidance for optimizing OIT protocols in clinical practice. Results will inform pediatric allergy guidelines and resource allocation, potentially reducing treatment burden and improving adherence. Strengths include focus on clinically relevant efficacy endpoints and strain-specific analyses. Limitations include potential language bias and heterogeneity in OIT/probiotic regimens. Systematic review registration: PROSPERO CRD420251247168