Cancer and Microbiota

Abstract

The human body is continuously exposed to both fixed and tran-sient microorganisms, as well as their toxic metabolites, which can lead to the appearance and progression of cancer at sites distant from the particular habi-tat of each microbe. Various scientific studies have made it possible to under-stand the close relationship that exists between the microbiome and cancer, since the components of the first, having the ability to migrate to different ar-eas of the body, can contribute to the development of various chronic diseases. Metagenomics studies suggest that dysbiosis, in the commensal microbiota, is associated with inflammatory disorders and various types of cancer, which can occur due to their effects on metabolism, cell proliferation, and immunity. The microbiota can cause cancer when predisposing conditions exist, such as in the initial stage of tumor progression (initiation), genetic instability, susceptibility to host immune response, progression, and response to therapy. The closest relationship between the microbiome and cancer, is through the dysregulation of the immune system. In this work, we review the current evidence on the association between the microbiota and some types of cancer such as gastric, colorectal, prostate, ovarian, oral, lung and breast cancer.