A Simple and Novel Fecal Biomarker for Colorectal Cancer: Ratio of to Probiotics Populations, Based on Their Antagonistic Effect.

BACKGROUND

Gut microbial dysbiosis contributes to the development of colorectal cancer (CRC). We evaluated the utility of fecal bacterial biomarker candidates identified by our 16S rDNA sequencing analysis for CRC diagnosis.

METHODS

We measured the relative abundance of (), (), (), and () by quantitative PCR in fecal samples from 2 cohorts of 903 individuals. We evaluated and validated the diagnostic performance of these microbial ratios and investigated the antagonistic effect of against 3 different indicator stains.

RESULTS

The microbial ratio of to () had a superior sensitivity of 84.6% and specificity of 92.3% in detecting CRC (area under the curve, AUC = 0.911). The combination of and improved the diagnostic value (AUC = 0.943). Moreover, the combination of and offered 60.0% specificity and 90.0% sensitivity in detecting stage I of CRC (AUC = 0.804). In particular, was negatively correlated with in the CRC group. The performance for CRC diagnosis was confirmed in the validation cohort II. The culture supernatant from exhibited strong bactericidal activity against probiotics and strains.

CONCLUSIONS

This study found that could play a role in microbiota dysbiosis via the secreted antagonistic substances against probiotics. Moreover, the ratio of to the important probiotics and was identified as a valuable biomarker for screening early CRC.