Dietary fiber.

It is obvious that the effects of fiber on colonic functions are complex. The typical "Western diet" which is high in fat and protein and low in fiber may alter the bacterial flora and milieu interieur of the gastrointestinal tract, particularly the colon, to produce a high incidence of colonic cancer. However, the exact nature of the interrelationships between these dietary constituents remains elusive and will undoubtedly be the subject of intense investigation in years to come.