Oral microbial functional dysbiosis in patients with CRA and CRC. (A) Differential KEGG pathways were analyzed using PICRUSt, and PCoA analysis was conducted for the three groups. Significant differences between CRC and CRA group (B), CRC and control group (C), and CRA and control group (D) were presented respectively. (E) Heatmap showing Spearman correlation coefficients of 20 genera shared among CRA, CRC, and healthy controls. (F) Bacterial co-occurrence and anti-occurrence were investigated and presented as a network, with nodes representing bacterial genera (colored according to phylum) and edges representing interactions (red = co-occurrence, blue = mutual exclusion) at p < 0.01. CRA, colorectal adenoma; CRC, colorectal cancer; PCoA, principal coordinates analysis; KEGG, Kyoto encyclopedia of genes and genomes.