Guo and colleagues reported that the microbial ratio of Fn to Bb Bifidobacterium (Fn/Bb) in their study had high sensitivity and specificity of 84.6% and 92.3%, respectively, in the detection of CRC while the combination of Fn/Bb and Fn/Fp Fecalibacerium prausnitzii gave a sensitivity of 90.0% and a reduced specificity of 60.0% in the detection of stage 1 (early) CRC. Here, FN1 is linked to colorectal carcinoma.