The human body is home to about 10 -100 trillion commensal bacterial organisms, of which about 70% reside in the gut. Growing evidence from animal and human studies suggest that these bacteria may contribute to the etiology of diseases such as colorectal cancer, a leading cause of cancer mortality in the United States. Although epidemiologic studies have implicated genetic factors and diet in the etiology of colorectal cancer, the findings from dietary studies have been inconsistent. It is reasonable that the inconsistencies in these dietary studies are related to the influence of the gut microbiota, a mostly understudied component. We hypothesize that the gut microbiota may contribute to the pathogenesis of colorectal cancer through interactions with diet, changes in community composition, production of toxic substances that lead to DNA damage and inflammation. Recent advances in molecular techniques make it possible to describe the gut bacterial communities and evaluate associations with diseases such as colorectal cancer. The presentation will review evidence for the role of gut bacteria in colorectal cancer, discuss potential mechanisms for the link between the gut bacteria and colorectal cancer and identify areas for future investigations.

Citation Information: Cancer Prev Res 2008;1(7 Suppl):CN15-02.

Seventh AACR International Conference on Frontiers in Cancer Prevention Research-- Nov 16-19, 2008; Washington, DC