Did you know that a common mouth microbe, Fusobacterium nucleatum, can promote colon cancer? This microbe – a player in gum disease, as well – has the potential to become pathogenic (harmful) when found in the gut.
But how? A recent study in Cell Host & Microbe points the way.
It’s the first study to identify how F. nucleatum becomes abundant in colorectal tumors, “colorectal” referring to any cancer of the bowels, colon, or rectum. Simply, the microbe uses a sugar-binding protein to stick to developing polyps and cancers. Once there, the microbes increase rapidly in numbers, accelerating disease.
And how do they get there? Via the bloodstream.
For the study, researchers used two groups of mice, one with precancerous colorectal tumors, the other with malignant ones. They injected F. nucleatum into the tail veins of each mouse and found that
the fusobacteria became saturated in the colorectal tumors of both types of mice when compared with the adjacent normal tissue.
The researchers also discovered that a protein on the surface of F. nucleatum has the ability to recognize a particular type of sugar that’s abundant on the surface of colorectal tumor cells. That protein, known as Fap2, guides how F. nucleatum colonizes the area.
This study lends weight to earlier research that identified F. nucleatum in the gut and suggested its connection with cancer – but without certainty of how the microbe got there in the first place. It had never been associated with cancer before.
Though more research is needed, this study paves the way to understand what guides F. nucleatum to tumors and why the microbe becomes abundant there. This understanding should contribute to the development of techniques that can not only block this action, but possibly guide and deliver cancer therapy directly to colon tumors.
Image by Hey Paul Studios, via Flickr