The Role of the Intestinal Microbiota in the Carcinogenesis of Colorectal Cancer

Aims There is growing evidence that the gut microbiota is one of the leading factors associated with colorectal cancer carcinogenesis. Etiological factors of CRC, in addition to genetic mutations, chronic inflammation, and exposure to carcinogens, include epigenetic imbalance, dietary changes, and immune system dysfunction. In recent years, there have been more and more studies on the pathogenesis of CRC based on microbiota.

Methods With the introduction of the 16s RNA sequencing technique of the intestinal microbiota, reliable data on the relationship of dysbiosis with carcinogenesis were obtained. According to the results of the study, the microbiota of patients with colorectal cancer contains significantly fewer varieties of bacteria than in healthy individuals.

Results The main mechanisms of neoplastic transformation of host cells are considered to be the synthesis of pathological metabolites by intestinal bacteria and the production of genotoxins (toxic reactive oxygen species and reactive nitrogen), as a result of which the repair mechanisms and apoptosis processes are disrupted. Chronic inflammation is considered a leading condition for the development of CRC, and a number of studies have shown that the 5-year cumulative risk of having inflammatory bowel disease (IBD) is 33 % - 54 %. It was reliably established that a decrease in the biological diversity and richness of the microbial component with an increase in the varieties of Fusobacterium (Fn), Peptostreptococcus, Bacteroides, Proteobacteria, Prevotella was observed in patients with CRC.

Conclusions The colon shows the highest bacterial density and diversity throughout the gastrointestinal tract, which may indicate an important role of the parietal microbiome in the pathogenesis of colorectal cancer. The mechanisms by which bacteria affect the colon mucosa are difficult and not fully understood. The combined use of epigenetic, microbiological, and metabolic technologies will make it possible to achieve a revolutionary breakthrough in the treatment, prevention, and prognosis of CRC in the future.

Citation: Karasev I, Vereshchak V, Davydkina T etal. eP251 THE ROLE OF THE INTESTINAL MICROBIOTA IN THE CARCINOGENESIS OF COLORECTAL CANCER. Endoscopy 2021; 53: S180.

Publication History

Article published online:
19 March 2021