Gut microbiota and carcinogenesis in various human organs

Scientific research in recent years has revealed a significant role of the human microbiome in carcinogenesis. These data served as a rationale for the inclusion of polymorphic microbiomes in the key characteristics of carcinogenesis as an important mechanistic determinant of cancer, in addition to other fundamental biological processes manifested during multi-stage carcinogenesis. The microbiome of the gastrointestinal tract is most actively involved in the pathogenesis of malignant neoplasms of the digestive system due to changes in the quantitative and qualitative composition of the microbiota, and increase in the production of genotoxic bacterial metabolites as factors of carcinogenesis. This review also addresses the changes in the microbiome in lung cancer, associated mainly with the production of short-chain fatty aicids, and in breast and endometrial cancers with specific changes in the composition of the bacterial community towar)ds species involved in the metabolism of estrogen precursors. The probable mechanisms of microorganisms’ participation in the development of prostate cancer (the effect of lipopolysaccharides, antibiotics and deconjugated estrogen) are considered.
Data on the relationship between the composition and metabolic characteristics of the microbiome in various cancer sites open up perspectives for its use in the diagnosis, treatment and prevention of malignant neoplasms and justify the need for further research in this area.