Effects of microbiota‐based interventions on depression and anxiety in children and adolescents—A systematic review

This study aims to systematically review evidence on gut microbiota-based interventions for reducing depression- and anxiety-like symptoms in children and adolescents with autism spectrum disorder, irritable bowel syndrome, Prader-Willi syndrome, below-average literacy skills or anorexia nervosa, where some individuals may exhibit indicators of depression or anxiety. This review includes evaluated evidence from randomized controlled trials (RCTs) involving children and adolescents aged 3–19 years, identified from PsycINFO, Medline (Ovid version), Web of Science, and the reference lists of existing reviews. Risk of bias were assessed using Risk of Bias Tool (RoB 2) in RevMan (version 5.4, Cochrane Collaboration). The results were qualitatively summarized by describing the main findings across the studies. Of the 1561 studies screened, 10 RCTs with 408 participants were included. Three gut microbiota-based interventions evaluated were probiotics, prebiotics, and dietary supplementation. Probiotics and dietary supplementation were identified as effective on reducing depression and anxiety in three studies; no significant effects were reported in the remaining seven studies. No evidence supported the effectiveness of prebiotics in reducing depression and anxiety in children and adolescents. Four studies presented low risk of bias, while others showed some bias in the randomization process, allocation concealment, selective reporting, and blinding of the outcome assessment. This review highlights the potential of probiotics and dietary supplements in treating depression and anxiety in children and adolescents. However, the current evidence is constrained by inadequate mental health measurements, participant heterogeneity, and small sample sizes in reviewed studies. Further well-designed studies are needed to confirm their effectiveness.