Prebiotics Rescue Gut Microbiome Dysregulation and Enhance Cognitive and Gastrointestinal Function in a Mouse Model of Schizophrenia.

Background and hypothesis: Schizophrenia is a devastating psychiatric disorder characterized by positive (eg, hallucinations) and negative (eg, reduced motivation) symptoms, and cognitive deficits. Chronic gastrointestinal tract issues exist as comorbid symptoms of schizophrenia. Recent findings indicate the involvement of the microorganisms that inhabit the gut, the microbiota (and the broader microbiome which also includes microbial genomes, etc.) in schizophrenia pathogenesis. In the present study, we hypothesized that chronic administration with prebiotics fructooligosaccharide and galactooligosaccharide (FOS and GOS; a combination used clinically for other disorders) would restore gut microbiome composition of the metabotropic glutamate receptor 5 (mGlu5) knockout (KO) mouse model of schizophrenia, which we previously demonstrated to exhibit gut dysbiosis.

Study design: We assessed the impact of prebiotics on gut microbiome composition and function, as well as the gastrointestinal function and schizophrenia-like phenotype of mGlu5 KO mice and wild-type littermates. We administered a combination of the prebiotics FOS and GOS, vs vehicle control administration, in both the mouse model of schizophrenia and wild-type littermates.

Study results: The present study firstly corroborated the altered gut microbiome composition in the mGlu5 KO mouse model of schizophrenia. Importantly, we have revealed an altered microbial metabolic profile. We have also shown that the prebiotics we administered were not only able to rescue these gut microbiome changes but also had additional beneficial effects including cognitive enhancement and improved gastrointestinal function.

Conclusion: These preclinical findings indicate that prebiotics, such as the combination of FOS and GOS used in the present study, may have therapeutic potential in schizophrenia as an add-on intervention with an exceptional safety profile.