Characterizing the Gut-Brain Axis in Schizophrenia: Microbiome Composition and Neuroinflammation in Nigerian Patients at Yaba Psychiatric Hospital

Emerging evidence implicates gut microbiome dysbiosis and resultant neuroinflammation in the pathophysiology of schizophrenia, yet no African gut-brain axis study in psychiatric populations has been conducted. This study characterizes gut microbiome composition and its relationship with neuroinflammatory markers in schizophrenia among patients at Psychiatric Hospital, Yaba, Lagos State, South West Nigeria. A case-control design will recruit 60 inpatients with schizophrenia and 60 age- and gender-matched healthy community controls. Stool samples will be collected and microbiome profiling performed using 16S rRNA gene sequencing with Illumina MiSeq. Serum neuroinflammatory markers including IL-1beta, IL-6, TNF-alpha, and brain-derived neurotrophic factor (BDNF) will be quantified by ELISA. Dietary intake will be assessed using a validated Nigerian food frequency questionnaire. Alpha and beta diversity indices will be compared between groups, and microbiome-neuroinflammation-psychosis symptom relationships will be explored using structural equation modeling. This study represents the first gut-brain axis investigation in a West African psychiatric population, constituting an original scientific contribution that may inform probiotic-based adjunctive therapy development for schizophrenia in Nigeria. Keywords: gut-brain axis, microbiome, schizophrenia, neuroinflammation, Nigeria