Indigestible Components of Grape Seeds Modify Cecal Enzyme Activity in Rats

Abstract

Background: The effect of grape seed indigestible fraction (GSIF) on cecal enzyme activity was studied. Methods: β-Glucuronidase, β-glucosidase, azoreductase, nitroreductase and nitrate reductase were measured in the cecal content of adult Wistar rats fed with a fiber-free diet supplemented with 5% cellulose or 5% GSIF as the source of dietary fiber for 4 weeks. Results: The intake of GSIF did not affect body weight gain nor food intake. However, GSIF caused a significant increase in cecal content, cecal wall and fresh and dry stool weight. Bacterial enzyme activities were lower in the GSIF-fed group than in the cellulose-fed group, although the difference was also significant for nitroreductase and β-glucuronidase. Conclusion: Adaptation to a diet containing GSIF led to changes in microbial activity that involved a decrease in reductive and hydrolytic enzymatic activities implicated in the conversion of procarcinogens into carcinogens.