Assessment of oncogenic role of intestinal microbiota in colorectal cancer patients.

INTRODUCTION: The direct association between some microbial species and cancers, such as in colorectal cancer (CRC), has been disclosed. OBJECTIVE: The aim of this study was to evaluate the changes in intestinal microbiota in subjects with CRC compared with healthy group. METHODS: Three-hundred fecal specimens were gathered from patients with CRC and 300 from healthy individuals during March 2014 to October 2019 from two hospitals in Tehran. The informed consent form and the questionnaire were completed by the patients. Following the identification of Lactobaccilus acidophilus (L. acidophilus), Lactobacillus palntarom (L. palntarom), and Enterococcus faecalis (E. faecalis), the number of bacteria was determined using quantitative real-time PCR (qPCR). RESULTS: The patients' age range was 20-76 years (mean: 55.34 ± 3.66). The qPCR clarified that number of E. faecalis was 2.2-fold higher in patients with CRC compared to healthy population (p = 0.0013). Additionally, the number of L. acidophilus and L. plantarom was 3.4-fold (p < 0.0001) and 4.8-fold (p < 0.0001) higher in healthy population. CONCLUSION: The inhibitory effect of intestinal microflora against the CRC development was proposed by observation of the changes in intestinal microbiota and determining their composition in subjects with CRC compared with that of healthy individuals. Microbiota was considered as a goal for the prevention and treatment of CRC. The relationship between microbiota and human health would be known deeper; this knowledge provides insights into the management of intestinal microbiota and therapeutics.