probiotic add-on therapy in the first-episode schizophrenia: a randomized controlled trial

Background: some evidence supports probiotics’ beneficial effects on clinical symptoms of patientswith schizophrenia and relieving unwanted frequently associated side effects of antipsychotic drugssuch as constipation, obesity, and metabolic disorders.objectives: this study aimed to assess the effect of probiotic supplements on clinical psychiatrysymptoms and metabolic indices in patients with schizophrenia.materials & methods: first-episode schizophrenic patients were randomly assigned to probioticsand placebo groups in a randomized controlled trial that took 12 weeks. the primary outcomes werethe brief psychiatric rating scale (bprs) change scores and positive and negative syndrome scale(panss). the secondary outcomes were clinical global impression-improvement scale (cgi-s),blood pressure (bp), body mass index (bmi), lipid profiles, and fasting blood sugar (fbs).results: a total of 62 patients were considered for the intention-to-treat analysis (mean age, 34.7years; 23 women; 39 men). the results showed no significant differences in the primary objectivesbetween the probiotic and placebo groups. in the probiotic group, subjects had lower levels of allbiochemical variables (triglycerides, cholesterol, and fbs) compared to the subjects in the placebogroup (standardized mean difference -4.3, -2.8, and -4.6, respectively; p<0.05).conclusion: we found that by adding probiotics to oral antipsychotics, bprs or panss scores do notimprove. however, cohen’s d for biochemical variables showed a medium to large effect size. thisstudy suggests probiotic supplementation may regulate and control triglycerides, cholesterol, and fbslevels. future studies are recommended to demonstrate these findings in the confirmatory analysis.