APOE and major depressive disorder: After adjusting for Wave 4 covariates of age, sex, education, BMI, ApoE ε4 status, alcohol use, smoking, physical activity score, diabetes, hypertension, stroke, PPI use, depression medication and antibiotic use, Mediterranean diet score, and fiber intake, we continued to observe an inverse association between high bowel frequency and GCS (β = −0.152, 95% CI: −0.276, −0.028, Padj=0.02) (Figure 2).