In addition, our pool results with three studies7, 17, 21 with 1085 patients found that high F. nucleatum levels in CRC tissue had no correlation with MLH1 hypermethylation (OR= 0.78, 95% CI: 0.06-9.93, P = 0.84) (supplemental Figure 2D). Here, MLH1 is linked to colorectal carcinoma.