Impact of probiotic treatment on clinical symptom reduction in schizophrenia: A systematic review and meta-analysis

source extracted confidence: high 2026-04-09
#probiotics #humans #schizophrenia #gastrointestinal-microbiome #randomized-controlled-trials-as-topic

Impact of probiotic treatment on clinical symptom reduction in schizophrenia: A systematic review and meta-analysis

Romero-Ferreiro et al., 2025 | J Psychiatr Res | Meta Analysis

Citation

Romero-Ferreiro Verónica, García-Fernández Lorena, ... Rodriguez-Jimenez Roberto. Impact of probiotic treatment on clinical symptom reduction in schizophrenia: A systematic review and meta-analysis. J Psychiatr Res. 2025-Feb;182:413-420. doi:10.1016/j.jpsychires.2025.01.050

Abstract

INTRODUCTION: Recent research has identified gut microbiota dysbiosis as a potential contributing factor in schizophrenia, leading to growing interest in exploring probiotics as a complementary approach to traditional antipsychotic treatments. This study aims to systematically evaluate the current evidence on the efficacy of probiotics in improving clinical symptoms of schizophrenia, offering a novel perspective into their potential role as an adjunctive strategy. METHODS: A systematic search was conducted to review randomized clinical trials, adhering to the PRISMA guidelines. A meta-analysis was also performed to assess the primary outcome, which was the impact of probiotic supplementation on clinical symptoms measured by the Positive and Negative Syndrome Scale (PANSS). RESULTS: Of the 76 studies initially identified, 5 were finally included. Regarding the symptomatology measured through the PANSS total score, the average effect was significant after the probiotic supplementation (standardized mean difference [SMD] = -0.608, (95% CI -1.314; -0.047), p = .035. CONCLUSION: The synthesis of available data suggests that probiotic supplementation may effectively reduce clinical symptoms in schizophrenia. However, the limited number of studies prevents the formation of robust conclusions. Further clinical trials with more rigorous experimental designs are necessary before making definitive recommendations.

Key Findings

Of the 76 studies initially identified, 5 were finally included. Regarding the symptomatology measured through the PANSS total score, the average effect was significant after the probiotic supplementation (standardized mean difference [SMD] = -0.608, (95% CI -1.314; -0.047), p = .035.

Outcomes Measured

  • Requires manual extraction

Population

Field Value
Population See abstract
Sample Size 76
Age Range See abstract
Condition See abstract

MeSH Terms

  • Probiotics
  • Humans
  • Schizophrenia
  • Gastrointestinal Microbiome
  • Randomized Controlled Trials as Topic
  • Outcome Assessment, Health Care

Evidence Classification

  • Level: Meta Analysis
  • Publication Types: Systematic Review, Journal Article, Meta-Analysis
  • Vertical: probiotics

Provenance

Source extracted via PubMed E-utilities API on 2026-04-09