A 12-weeks Study to Evaluate the Dietary Fiber and Probiotics Treatment in Prevention and Intervention of Weight-gain and Cognitive Impairment of Schizophrenia or Bipolar Disorder

In this study, the investigators will evaluate the efficacy, safety and related mechanism of dietary fiber and probiotics alone and in combination as a add-on treatment in improving the antipsychotic induced weight gain, the cognitive impairment, and psychotic syndrome in schizophrenia or bipolar disorder patients. The study will recruit 100 schizophrenia or bipolar disorder patients who meet the criteria of DSM-5, and then randomized to 4 groups: probiotics group(PB group) dietary fiber group(FB group) probiotics plus dietary fiber group(PF group) and control group(CT group) for a 12-weeks clinical trail (20 patients per arm) for a 12-weeks clinical trail. Clinical efficacy and safety assessment will be done at screen/baseline, 4 week, 8 week and 12 week. The specific aims are to compare probiotics group versus controls on: 1) clinical core symptoms; 2) cognition; 3) metabolic related markers. Biological samples also will be collected, and stored to research related mechanisms. Clinical symptoms will be measured by the Positive and Negative Syndrome Scale,. Cognitive function will be assessed by the MATRICS Consensus Cognitive Battery.

The investigators hypothesize that: 1) dietary fiber and probiotics may improve cognitive impairment of patients with schizophrenia; 2) dietary fiber and probiotics could prevent the cognitive decline of patients with schizophrenia; 3)dietary fiber and probiotics may prevent the antipsychotics induced weight gain in patients with schizophrenia.4)dietary fiber and probiotics may alter oxidative stress indexes or inflammatory biomarkers thus influence the oxidative and inflammatory mechanism.