Changes in metabolism and microbiota after 24-week risperidone treatment in drug naïve, normal weight patients with first episode schizophrenia.

OBJECTIVE

This study was to examine the alterations in metabolic parameters, anti-oxidant superoxide dismutase (SOD), inflammatory marker high-sensitivity C-reactive protein (hs-CRP) and microbiota after 24-week risperidone treatment in drug naïve, normal weight, first episode schizophrenia patients; the study further examined the relationship between metabolic changes and changes in microbiota.

METHODS

Forty-one patients completed the 24-week study and 41 controls were enrolled in this study. Metabolic parameters, SOD, hs-CRP and the copy numbers of 5 fecal bacteria were measured at baseline (both groups) and at different time points (patients only).

RESULTS

Patients had significantly lower numbers of fecal Bifidobacterium spp., Escherichia coli, Lactobacillus spp. compared with healthy controls (HC) (ps < 0.001); in contrast, the numbers of fecal Clostridium coccoides group were significantly higher in the patient group compared with HC (p < 0.001). After 24-week risperidone treatment, there were significant increases in body weight, BMI, fasting blood-glucose, triglycerides, LDL, hs-CRP, SOD and HOMA-IR (p < 0.001), significant increases in the numbers of fecal Bifidobacterium spp. and E. coli (ps < 0.001), and significant decreases in the numbers of fecal Clostridium coccoides group and Lactobacillus spp. (ps < 0.001). Hierarchical multiple linear regression analysis shows that after controlling for potential confounding variables, only the changes in fecal Bifidobacterium spp., among 4 types of fecal bacteria, entered into the model and significantly correlated with the changes in weight (unstandardized coefficient B = 4.413, R2 change = 0.167, p = 0.009) and BMI (B = 1.639, R2 change = 0.172, p = 0.008) after 24-week treatment.

CONCLUSION

Drug naïve, first episode schizophrenia patients show abnormalities in microbiota composition. Risperidone treatment causes significant changes in certain fecal bacteria, which are likely associated with antipsychotic medication induced metabolic changes.