Quantification of Enterococcus Faecalis and Fusobacterium Nucleatum in Healthy Colorectal Tissues Compared with Polyp and Cancer Colorectal Tissues

Colorectal Cancer (CRC) is the second most common cancer in men and women. Recently, investigations have revealed a much larger role for epigenetic and non-hereditary factors in CRC incidence than hereditary factors. Among all nonhereditary factors, gut microbiota alterations are the most prominent factor in the development of CRC. This work aimed to study the quantification of Enterococcus faecalis and Fusobacterium nucleatum in healthy colorectal tissues compared with polyp and cancer colorectal tissues of Iranian peoples.

In this case-control study, 21 biopsy samples of normal colon tissue, 21 polyp tissues, and 19 tumor tissues were investigated. To quantify the Enterococcus faecalis and Fusobacterium nucleatum in our samples, we employed the 16SrRNAspecific gene in Real-Time Quantitative PCR method.

The Quantitative Real-Time PCR results demonstrated a significant increase (P-value<0.05) in the population of both bacterial species, Enterococcus faecalis and Fusobacterium nucleatum in tumor and polyp tissues compared with normal samples. In addition, the Spearman index for these two species was 0.7634, which refers to a synergistic relationship between these species in the colon environment.

Collectively, by the progression of CRC, the abundance of Enterococcus faecalis and Fusobacterium nucleatum, will be increasing. In other words, the enrichment of these species can induce the development and progression of CRC and might be a sign of its occurrence.