Investigating the gut microbiome in patients with schizophrenia

Growing evidence suggests a complex interplay between the gut microbiome and schizophrenia (SCZ) through the microbiome-gut-brain axis. Dysbiosis of the gut microbiome has been observed in SCZ patients, indicating potential associations between specific microbial profiles and disease severity. This study aims to investigate the intricate connections between the gut microbiome and SCZ. 16S rRNA (V4) sequence data for 41 patients with SCZ (first-episode psychosis, FEP, n = 24; chronic patients n = 17) and 48 controls from the Shared Roots of Neuropsychiatric Disorders and Cardiovascular Disease Project (SR) were analysed. Patients were recruited from general and psychiatric hospitals and community clinics. The diagnosis of SCZ was based on the Structured Clinical Interview for the Diagnostic and Statistical Manual of Mental Disorders, fourth edition (SCID-IV). Data analysis was done in R studio (dada2 pipeline) and QIIME2 (diversity and composition plugins) to assess diversity (PCoA and adonis PERMANOVA) and differential abundances (ANCOM and ANCOM-BC). Covariates included in the analyses were case-control status, sex, and current smoker status. We found no significant results for cases versus controls, or for FEP versus chronic cases. The results did suggest that Alistipes (p = 0.064) were enriched in SCZ cases versus controls. Moreover, the results suggested the differential abundance of Methanobrevibacter (p = 0.068) and Butyrivibrio (p = 0.083) were depleted in FEP cases, whereas Gemmiger (p = 0.098) was enriched in chronic cases compared to controls. This is an exploratory study done on a South African population and larger studies are needed to confirm the findings of the gut microbiome's association with case-control statuses and Methanobrevibacter, Butyrivibrio, Gemmiger, and Alistipes.