Significance of Cecectomized Rats in Nutritional Studies

Abstract

Rats have an enlarged cecum to be considered as an adaptive structure to variable food quality. The cecum plays an important role to utilize indigestible and fermentable food materials in the rat. Cecectomy results in faster transit of digesta connecting lower digestibilities of food components in the rat. The response of the transit and retention of digesta to the feeding of indigestible food materials is similar to that in human, where the inverse response is often recognized in normal rats, suggesting that cecectomized rats are useful in the study concerning digesta movement in the gut. Some of nutritional and physiological effects of dietary fiber and fermentable food components are extinguished by cecectomy. Some inverse results are obtained in the rats with or without cecum in the nutritional and physiological studies. Fermentation in the large gut is modified largely by cecectomy. Although the cecectomized rat has some possibilities as a useful experimental animal, there is a limitation to use the cecectomized rat as an experimental animal in the study of the function of fermentable food materials. Further comparative studies are needed in the functions of the digestive tract between human and the cecectomized rat for the strict qualification of the usefulness in human nutrition studies.