Are we any closer to screening for colorectal cancer using microbial markers?A critical review.

The role of gut microbiota in the development of sporadic colorectal cancer (CRC) is supported by a number of studies, however, the conclusiveness of published metagenomic studies is questioned by technical pitfalls and limited by small cohort sizes. In this review, we evaluate the current knowledge critically and outline practical solutions. We also list candidate CRC risk markers that are - in our opinion - well supported by available data and thus deserve clinical validation. Last but not least, we summarise available knowledge useful for improving care for patients immediately.