Intestinal carcinogenesis and dietary fibers: The influence of cellulose or Fybogel chronically given after exposure to DMH

Abstract

This study was initiated to analyze the effect of a) two characterized vegetal fibers [i.e., a polysaccharide (cellulose) and a mucilaginous substance (Fybogel)], which were b) added at two concentrations (5% and 15% wt/wt), c) as constituents of low (5% wt/wt) and high (20% wt/wt) fat isocaloric diets d) given chronically to rats one week after the administration of 1,2‐dimethylhydrazine (DMH) DMH had previously been injected once a week for 15 weeks to induce intestinal carcinogenesis. The dietary consumption, the body weight, and the fecal outflow showed a similar and regular evolution for the rats of all experimental groups; the exception was those receiving the 20 % lipids‐15 % Fybogel diet. That specific diet caused a decrease in body weight concomitant with an increase in dietary consumption and in fecal outflow. The variation in fecal outflow depended on fat and fiber concentrations. The mucilage was more degraded, in absolute and relative amount, than was cellulose when this polysaccharide was included at a 20% lipid diet. Concerning the effect of these two fibers on intestinal carcinogenesis, Fybogel showed an anticarcinogenic property, whereas cellulose did not. The inhibitory activity of Fybogel was on the incidence of intestinal and colonic tumors as well as on the colonic tumor yield. Moreover, it slowed down the rate of colonic formation.