Fig. 4

Genus alterations in PDs in the context of basic covariates and clinical variables. a Boxplots of Paraprevotella and Bifidobacterium for cases and controls in dependence of sex and constipation, respectively. In both cases, differences in mean abundance had FDR < 0.05. b Scatter plots and non-linear regression lines for cases and controls of genus abundances of Anaerotruncus, Roseburia, and Paraprevotella in dependence of age and BMI. Global test (Wald test, testing all interaction terms simultaneously on zero) had an FDR < 0.05 in all three cases. For graphical assessment of the interaction terms, the z-transformed residual abundances are displayed after correction for technical covariates (batch and read counts). c Error bar plots of Paraprevotella and Bilophila abundances in dependence of disease staging. Genus association with disease staging showed a decrease of relative abundance of Paraprevotella and an increase of Bilophila genus over increasing Hoehn and Yahr scale values (FDR < 0.05). Error bars represent 95% confidence intervals. d Scatter plots of motor symptoms (UPDRS-part III) were positively associated with of Flavonifractor and Peptococcus abundances and negatively with Paraprevotella abundance (FDR < 0.05). UPDRS, Unified Parkinson Rating Scale; BMI, body mass index; FDR, false discovery rate