Gut-Brain Axis Interventions in Pediatric Psychosomatic Disorders: A Systematic Review and Meta-Analysis of Gastrointestinal vs. Non-Gastrointestinal Symptom Outcomes

Psychosomatic symptoms in children and adolescents are increasingly linked to the
gut-brain axis, prompting exploration of microbiome-based interventions like probiotics,
prebiotics, dietary modifications, and fecal microbiota transplantation (FMT). This systematic review evaluated their efficacy in reducing gastrointestinal and non-gastrointestinal psychosomatic symptoms in pediatric populations (aged 0–18years) through a comprehensive search of PubMed, Embase, Scopus, CENTRAL, and EKB up to 10 May 2025 for randomized controlled trials (RCTs). Ten RCTs (n=512) were included, with two reviewers independently selecting studies, extracting data, and
assessing risk of bias using the RoB 2 tool. Standardized mean differences (SMDs) were pooled using random-effects models in RevMan 5.4, showing significant reductions in gastrointestinal symptom severity (SMD-0.52, 95% CI-0.78 to-0.26; I2=62%; 8
studies, using VAS and IBS-SSS) and smaller reductions in non-gastrointestinal symptoms (SMD-0.38, 95% CI-0.61 to-0.15; I2=55%; 6 studies, using PedsQL and SCARED), with probiotics yielding the largest effect sizes. Despite low evidence
certainty due to study heterogeneity, these findings support microbiome-based interventions, particularly probiotics, for reducing psychosomatic symptom severity, especially gastrointestinal symptoms, and highlight the need for more rigorous,
standardized trials to inform clinical approaches to pediatric psychosomatic care.