Probiotic supplements reduce antipsychotic-induced metabolic disturbances in drug-naive first-episode schizophrenia

Probiotic supplements have demonstrated efficacy in improving metabolic abnormalities and may prevent antipsychotic-induced metabolic disturbance and weight gain. A few studies in rodents have found that antipsychotic-induced metabolic dysfunctions are associated with the altered composition of gut microbiota. Here, we conducted a randomized-controlled clinical trial to determine the effectiveness and safety of probiotic supplements on antipsychotic-induced metabolic disturbance and weight gain. Patients with drug-naive first-episode schizophrenia were randomized to receive either olanzapine plus probiotics or olanzapine monotherapy and scheduled to evaluate with follow-ups for clinical and metabolic profiles. After a treatment of 12 weeks with addition of probiotics, the increase of mean fasting insulin was significantly lower than olanzapine monotherapy. Insulin resistance increased considerably in the olanzapine plus probiotics, but also significantly lower than olanzapine monotherapy. We noted a difference in the increase in body mass index and body weight between treatments at a nominal level of significance, but it became non-significant after adjusting for appetite increase. Probiotics concurrently used with olanzapine is effective and safe in attenuating antipsychotic-induced elevation of fasting insulin and insulin resistance, but not the weight gain in drug-naive first-episode schizophrenia. Further study is warranted to assess the longer-term maintenance of efficacy and safety.