Gut Microbiome Composition and Obesity Risk in Nigerian Adults: A Comparative Cross-Sectional Study in Abuja

Emerging evidence implicates gut microbiome composition as a mediating factor in obesity pathophysiology through mechanisms including short-chain fatty acid production, energy harvest, and immune modulation. Despite a growing global literature, gut microbiome research in sub-Saharan African populations remains sparse, limiting the generalisability of findings to Nigerians. This study compares gut microbiome composition between obese and normal-weight adults in Abuja, Federal Capital Territory, and examines associations with dietary patterns and metabolic markers. A comparative cross-sectional design enrolled 120 adults aged 25 to 55 years, comprising 60 obese participants with a body mass index of 30 or above and 60 normal-weight controls with a body mass index between 18.5 and 24.9, matched for age and sex. Gut microbiome composition was characterised using 16S rRNA gene sequencing of stool samples, with alpha and beta diversity analyses and taxa-level comparisons performed. Dietary intake was assessed using a validated food frequency questionnaire, and dietary patterns were derived using principal component analysis. Metabolic markers including fasting blood glucose, insulin, lipid profile, and leptin were measured from fasting venous blood. Associations between dietary patterns, microbiome diversity indices, and metabolic markers were examined using Spearman correlations and multivariate regression. Findings will generate preliminary data on the relationship between diet, the gut microbiome, and obesity in Nigerian adults, contributing to a poorly characterised research area in West African nutrition science. Keywords: gut microbiome, obesity, dietary patterns, Abuja, 16S rRNA sequencing.