Bacterial biofilm formation inside colonic crypts may accelerate colorectal carcinogenesis

Hans Raskov, Kasper Nørskov Kragh, Thomas Bjarnsholt, Mahdi Alamili, Ismail Gögenur

Research in the field of relation between microbes and colorectal carcinogenesis has gained increasing interest in past years. Recently, link between microbial biofilm and carcinogenesis in colon was demonstrated by several authors indicating that biofilm not only is a key player in carcinogenesis, but also may contribute to the understanding of side-specific colon cancer-right sided colon cancer versus left sided. In this article, we briefly highlight the major findings of the research of biofilm and carcinogenesis and demonstrate our findings of colonic cancer tissue and colonic polyp examined for biofilm. Colonic cancer tissue from a patient with a right-sided colon cancer, and an adenoma tubular polyp were examined for biofilm formation by flourescens in situ hybridization. In cancer tissue we found biofilm formation on the surface epithelium but surprisingly also deep into the crypts. No biofilms were found in tubular polyp tissue. To our knowledge, this is the first-time biofilm formation deep into colonic crypts are demonstrated in a patient with right-sided colon cancer. This may indicate that bacterial biofilm may have a key role in carcinogenesis.