Fig. 2: Gut CAZymes features can distinguish MDD and HC.

Using random forest model, 9 CAZymes were identified with importance score >1%. a Volcano plot for differential CAZymes markers. Significantly regulated metabolites between groups determined by fold change and value of p (FC > | 1.5 | , p < 0.05). Gray dots represent increased CAZymes in HC; green dots represent increased CAZymes in MDD. b The box plots showed the differences of 9 CAZymes markers (Wilcoxon rank-sum test). c A random forest model was constructed and displayed by ROC. In the discovery set, individual signature could discriminate the two groups with area under the curve (AUC) at 0.824, the value in brackets is 95% CI. The diagnostic efficiency was confirmed by 5 fold cross validation test (accuracy: 65.24 ± 7.72%). d Correlation-based networks of co-occurring MDD-related CAZymes colored by node affiliation, a co-varying cluster was composed of 6 GHs in MDD subjects. A node stands for an CAZyme and a connection (i.e. edge) stands for a significant (pearson’s r > 0.2 or <-0.2, p < 0.05) pairwise correlation. Size of the nodes represents the rpkm of these variables. Edges between nodes indicate pearson’s positive (green) or negative (gray) correlation, edges thickness indicate range of p-value (p < 0.05).