Role of Gut Microbiome in Colorectal Cancer

Abstract

Although colorectal cancer (CRC) incidence rates and mortality had been steadily declining from 1999 to 2015, in the United States (USA), this neoplasm disease is the third most common cancer diagnosed in both men and women globally. Various genetic and environmental factors contribute to the initiation and progression of CRC, including hereditary elements, familial history, inflammation, and gut microbiome. Intestinal tract is a unique ecosystem of co-existing various host cells with complex microbiota communities and their metabolic products. A large body of knowledge has accumulated to indicate that members of dysbiosis microbiota express virulence factors, disrupt host cellular genetic stability, and directly induce tumorigenesis. Dysbiosis also promotes CRC through exacerbating intestinal inflammation, tumor initiation, and progression. On the other hand, increasing lines of evidence show that members of beneficial microbiota resist the dysbiosis detrimental actions. In this chapter, we review the current status of CRC, microbiome, the influence of microbiome on intestinal inflammation, and tumorigenesis. The purpose of this chapter is to provide updated knowledge on CRC and host–microbiome interaction at the interface of CRC prevention and treatment.