Influence of high dietary cellulose on fecal glycosidases in experimental rat colon carcinogenesis.

The effect of either high-cellulose (15%) or regular-cellulose (5%) diets on fecal bacterial glycosidases was assessed in two groups of ten Wistar rats, each given an injection of 1,2-dimethylhydrazone, and in two groups of six control rats. During a 4-month period, fecal activities of bacterial beta-galactosidase and beta-acetylglucosaminidase were reduced markedly in control rats maintained on the high-cellulose diet. Enzyme differences were even more significant in rats fed high- or regular-cellulose diets and given injections of the carcinogen. This decrease in fecal bacterial enzymes induced by a high-cellulose diet was observed as early as 20 days after initiation of the diet. Lowering of bacterial beta-glycosidases by a high-cellulose diet may preserve the glycoprotein integrity of colonic cells. It may also reduce the luminal production of potential mutagens from dietary beta-glycosides in the colon. The latter has been postulated as an important mechanism in colonic tumor development.