Romero Ferreiro, VerónicaGarcía Fernández, LorenaRomero, CarmenFuente Del Rey, María Mónica De LaDiaz del Cerro, EstefaníaScala, MauroGonzález Soltero, RocíoÁlvarez Mon, Miguel ÁngelPeñuelas Calvo, InmaculadaRodríguez Jiménez, Roberto2025-03-042025-03-042025-01-24Romero-Ferreiro, V., García-Fernández, L., Romero, C., De la Fuente, M., Diaz-del Cerro, E., Scala, M., González-Soltero, R., Álvarez-Mon, M. A., Peñuelas-Calvo, I., & Rodriguez-Jimenez, R. (2025). Impact of probiotic treatment on clinical symptom reduction in schizophrenia: A systematic review and meta-analysis [Review of Impact of probiotic treatment on clinical symptom reduction in schizophrenia: A systematic review and meta-analysis]. Journal of Psychiatric Research, 182, 413-420. Elsevier Ltd. https://doi.org/10.1016/J.JPSYCHIRES.2025.01.0500022-395610.1016/j.jpsychires.2025.01.050https://hdl.handle.net/20.500.14352/118443This research was supported in part by the by the Instituto de Salud Carlos III (PI19/00766; Fondo de Investigaciones Sanitarias/FEDER), by the European Development Regional Fund ‘‘A way to achieve Europe’’ (ERDF), by Madrid Regional Government (R&D activities in Biomedicine P2022/BMD-7216 (AGES-CM 3-CM)) and Structural Funds of the European Union, by CIBERSAM-III.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.engjournal article1879-1379https://doi.org/10.1016/j.jpsychires.2025.01.050https://www.sciencedirect.com/science/article/pii/S0022395625000585?via%3Dihubrestricted access579.8579.67616.89616.895.8616.3SchizophreniaPsychosisProbioticsBifidobacterLactobacillusPANSSPsiquiatríaTecnología de los alimentosBiotecnología3211 Psiquiatría3205.03 Gastroenterología3309.90 Microbiología de Alimentos