Inhibitory effect of dietary carboxymethylcellulose on fat digestibility in rats fed diets containing either starch or glucose

Dietary carboxymethylcellulose (CMC) inhibits lipid digestibility in broiler chickens by increasing the viscosity of small intestinal digesta. The aim of this study was to investigate the effect of dietary CMC on lipid digestibility in rats fed diets containing either starch or glucose. It was hypothesized that CMC would have a greater inhibitory effect on lipid digestibility when the diet contained starch instead of glucose. Male rats were fed for 2 weeks purified diets containing either 619.2 g starch or glucose per kg and CMC levels of either 0, 20 or 40 g/kg. The experimental diets had no differential effect on growth of the rats. CMC significantly lowered the apparent lipid digestibility coefficient by more than 0.1, this effect being independent of the type of carbohydrate in the diet. Lipid digestibility was significantly reduced by glucose when compared with starch, but the mechanism is unknown.