Abstract
The viscosity of gut contents may affect the rate of digestion and absorption by reducing the diffusion rate of food components, digestive enzymes and nutrients. Our previous study showed that the content of large solid particles in digesta was positively correlated with the viscosity of pig cecal contents in vitro. The purpose of the present study was to examine the contribution of dietary solid particles such as cellulose to the viscosity of gut contents and to intestinal tissue weight in vivo. Using an E-type viscometer, we estimated the coefficient of viscosity of gastric, small-intestinal and cecal contents with solid particles in rats fed a purified polymeric diet containing 0, 11 or 13% cellulose. We also assessed the effect of cellulose ingestion on the weight of the mucosa, submucosa, and muscularis externa in the intestinal tissue of rats by morphometry. Ingestion of cellulose increased the coefficient of viscosity of small-intestinal and cecal contents (p<0.05), and the weight of colonic mucosa (p<0.05). These findings indicate that ingestion of solid particles increases the viscosity of gut contents in vivo.
