Fig. 2

Comparison of microbial profiles between QC samples, TC tumor and matched peritumor tissues before elimination of environmental contamination. A, B Chao1 and Shannon indices were used to evaluate the microbial diversity of the paired tumor, peritumor tissues, and QC samples. Tumor and matched peritumor tissues were from 30 TC patients. QC samples were used to reveal the environmental microbiota. The Mann–Whitney U test was performed to compare differences between two groups. C Principal coordinate analysis (PCoA) of Bray–Curtis analysis demonstrated that QC samples, peritumor and tumor tissues showed three distinct clusters. The microbial relative abundance of TC tumor tissues, matched peritumor tissues, and QC samples at the phylum (D) and genus (E) levels is shown