In a paper published in JAMA oncology, Doctor Raaj Mehta and colleagues from Harvard Medical School (USA) suggest that a diet rich in fiber and whole grains could influence the risk of developing colorectal cancer linked to a strain of gut bacteria called Fusobacterium nucleatum. Fusobacterium nucleatum is an inflammatory bacterium that is thought to play a role in colorectal cancer by blocking the immune response triggered to combat tumor cells in the colon. By studying the diets of 137,217 people over approximately 30 years, and analyzing 1000 samples from colorectal tumors and their Fusobacterium nucleatum levels, the Harvard researchers found that individuals eating diets rich in whole-grain cereals and fiber had a lower risk of developing colorectal cancer containing this particular type of bacteria.