Associations of body fat percentage-based obesity with depression and comorbidity-related gut microbiota features in college students.

INTRODUCTION

The association between body fat percentage (BFP)-defined obesity and depression in college students remains unclear, and gut microbiota alterations in this comorbid condition have not been fully characterized.

METHODS

A total of 906 college students were recruited to examine the prevalence of comorbid obesity and depression and the association between body fat percentage-defined obesity and depression. Logistic regression was used for association analysis. Subsequently, 104 participants balanced for age and sex distributions across groups were selected and divided into four groups: obese with depression (G1), non-obese with depression (G2), obese without depression (G3), and non-obese without depression (G4). Fecal samples were analyzed by 16S rRNA gene sequencing.

RESULTS

The prevalence of comorbid obesity and depression was 9.71%. BFP-defined obesity was significantly associated with depression after adjustment for covariates (OR = 1.62, 95% CI: 1.10-2.38). Gut microbiota analysis showed no significant differences in α-diversity among groups, whereas β-diversity differed significantly between the G1 and G4 (P < 0.05). Descriptive taxonomic profiles suggested differences in the relative abundances of several genera (e.g., decreased Akkermansia, increased Fusobacterium and Collinsella in G1). PICRUSt- based functional prediction suggested differences in inferred microbial metabolic pathways between G1 and other groups, including higher predicted lipopolysaccharide biosynthesis pathway abundance than in G2 and G4.

DISCUSSION: BFP-defined obesity was associated with depression in college students. The microbiome findings were exploratory and suggest that co-occurring obesity and depression may be associated with differences in gut microbial composition and predicted functional potential. Larger longitudinal studies with direct functional and inflammatory measurements are needed.