Fig. 2

Microbial comparison of paired tumor and paired-normal tissues from patients with ESCC for α (A) and β diversity (B). The α diversity of 21 paired ESCC tumor and nontumor tissues was assessed with the Chao1 index, Shannon index, observed species and PD_whole_tree. The β diversity, based on the bray-curtis distance, was compared with PCoA plots for 21 paired tumor and nontumor tissues from patients with ESCC. PCoA, principal coordinate analysis. (C) The relative abundance of bacteria at the phylum level in both the normal and tumor groups of ESCC. (D) Differential abundance analysis revealed that Bacteroidetes (P = 0.03149), Fusobacteria (P = 0.01796) and Spirochaetae (P = 0.004155) were the top 3 significantly enriched taxa in the tumor group compared with the matched normal group samples. **P-value< 0.01