A New Era of Fibers in the Prevention of Colorectal Cancer

Several studies have indicated a role for diet in the etiology of colorectal cancer. Dietary fibers are a heterogeneous group of compounds consisting of the remnants of plant cells resistant to hydrolysis by human alimentary enzymes which were suggested to play a role in colorectal cancer prevention. While different observational and prospective cohort studies in the 1980s and '90s suggested a protective role for dietary fibers, most of the recent meta-analyses and large studies do not support this notion. New approaches such as identifying food patterns, identifying specific chemical compounds in the food, and studying differences in food processing may help in identifying such a role. Other new approaches include studying the immunologic properties of fibers and the effect of gut microbiota, which is affected by the content of fibers in the diet.