Exploring the relationship between the gut microbiota and cognitive function in schizophrenia patients with distinct weights.

Background: The gut microbiota is disrupted in schizophrenia (SZ) patients and is associated with cognitive function. This study aimed to investigate the gut microbiota composition in SZ patients with different body mass index (BMI) levels and their associations with cognitive function.

Methods: We analyzed 16S rRNA sequencing data from 156 SZ patients, including 88 with overweight/obesity (OW) and 68 with normal weight (NW), and 156 normal control (NC), including 48 with OW and 108 with NW. We analyzed differences in microbial diversity and gut microbiota composition between SZ patients and NC at different BMI levels. Additionally, we explored the correlations between microbial communities, and symptom severity, as well as cognitive function. Furthermore, we examined between-group differences in metabolic pathways.

Results: The abundance of Turicibacter was higher in the SZ_OW group but lower in the SZ_NW group compared to the NC groups at the same BMI level, respectively. In the SZ_OW group, increased Collinsella was significantly negatively associated with cognitive function, whereas decreased Clostridium and Butyricicoccus were significantly positively associated with cognitive function. Additionally, the functional analysis revealed enrichment of "metabolism of other amino acids" and "neurodegenerative disease" pathways, associated with non-standard amino acid metabolism and oxidative stress in the SZ_OW group compared to the NC_OW group.

Conclusions: Our findings revealed significant differences in the gut microbiota between SZ patients and NC with different BMI levels and identified microbial associations with clinical characteristics, providing new insights into the mechanism of how the gut microbiota could impact cognitive deficits in SZ patients with obesity.