How the microbiome is shaping our understanding of cancer biology and its treatment

The human body is a metaorganism: it is composed of the individual and the individual's microbiome. Therefore, the study of malignancy within a metaorganism must include an understanding of the microbial contribution to tumorigenesis, response to treatment, and ultimately recurrence. The colon and rectum harbor more microbes than any other anatomic system, and the interplay of microbes with colorectal cancer has emerged as an exciting area of research. This article highlights the leading theories on the microbial contribution to colorectal tumorigenesis and proposes novel, therapeutic strategies for the future treatment of this disease.