Intestinal microorganisms, diet and cancer

A new study published in JAMA Oncology provides some of the strongest evidence to date that microorganisms in the large intestine can play a role in colorectal cancer.  The lead authors at Dana-Faber Cancer Institute and Massachusetts General Hospital tracked 137,000 people over many decades and found that individuals with a diet rich in whole grains and fibre had a lower risk of colorectal cancer.  The study also examined more than 1000 tumour samples for a bacteria, F nucleutum.  The study found that individuals consuming diets rich in whole grains and fibre altered their relative amounts of various microorganisms in the digestive tract, including F nucleutum.

Researchers stated "Though our research delt with only one type of bacteria, it points to a much broader phenomenon, that intestinal bacteria can act in concert with diet to reduce or increase the risk of certain types of colorectal cancer."

Andrew Chan, MD, MPH of Massachusetts General Hospital and The Broad Institute of MIT and Harvard added "These data are among the first in humans that show a connection between long term dietary intake and the bacteria in tumour tissue.  This supports earlier studies that show some gut bacteria can directly cause the development of cancers in animals." 

About the journal:  JAMA, the journal of the American Medical Association is a peer reviewed medical journal published by the American Medical Association.