α-diversity of the gut microbiota of the study population categorized by adherence to the Dutch physical activity (PA) guideline (red dots, sedentary participants, n = 440 (one participant with missing value for BMI was excluded); blue dots, active participants, n = 868) based on the Short Questionnaire to Assess Health-enhancing physical activity (SQUASH): (a) Shannon index α-diversity (p = 0.042, covariate adjusted p = 0.3); (b) Richness (p = 0.032, covariate adjusted p = 0.9). Wilcoxon test was used as a statistical test to compare active group vs. sedentary group. Covariates used: ethnicity, age, sex and body mass index (BMI).