Fig. 6: Differential metabolite and metabolic pathway analysis.
a 3D PCA score plots between normal, high-risk and low-risk groups. b Heatmap of differential metabolites along the normal, high-risk and low-risk groups (red: increased concentration; blue: decreased concentration). OPLS-DA score plots comparing CRC group vs. normal group (c), and high-risk group vs. low-risk group (d). (e-f) Statistical validation of the corresponding model by permutation analysis (999 times). The x-axis represents the permutation retention rate of the permutation test, and the dots in the upper right corner represent the R2 (light blue) and Q2 (dark blue) values of the original model when the permutation retention rate was 1. R2 measured the goodness of fit, while Q2 measured the predictive ability of the model. Light blue dots represented the R2 value obtained from the permutation test, while dark blue dots represented the Q2 value obtained from the permutation test. The two dashed lines represented the regression lines of R2 and Q2, respectively. Metabolic pathway analysis comparing CRC group vs. normal group (g) and high-risk group vs. low-risk group (h). Pathway topology was assessed using relative betweenness centrality. Each bubble represents a pathway, with bubble color and size indicating p-value and impact value, respectively. i Venn diagram showing 17 overlapping differential metabolites between CRC group vs. normal group and high-risk group vs. low-risk group. j Sankey-bubble chart of 11 significantly enriched metabolites and their 6 associated metabolic pathways. CRC colorectal cancer, PCA principal component analysis, OPLS-DA orthogonal partial least squares discrimination analysis.
