Microbes in the gut help to boost the risk of colon cancer when haem, the pigment found in red meat, is present.
Haem in the diet has been linked to an increased risk of colon cancer — the pigment damages cells lining the gut, which leads to excessive cell proliferation. Noortje Ijssennagger at University Medical Center Utrecht in the Netherlands and her colleagues fed mice a diet containing haem and found that animals that also received antibiotics did not have this gut damage or increased cell proliferation. Haem increased the level of a bacterium called Akkermansia muciniphila, which breaks down the gut mucus lining, exposing gut cells to the damaging haem. Gut bacteria that produce sulfide also degrade this mucus barrier.
Using a biomarker to monitor gut mucus degradation could be a way to gauge colon-cancer risk, the authors say.
Proc. Natl Acad. Sci. USA http://doi.org/6jp (2015)