Rats have an enlarged cecum to be considered as an adaptivestructure to variable food quality. The cecum plays an importantrole to utilize indigestible and fermentable food materials in therat. Cecectomy results in faster transit of digesta connectinglower digestibilities of food components in the rat. The responseof the transit and retention of digesta to the feeding ofindigestible food materials is similar to that in human, where theinverse response is often recognized in normal rats, suggestingthat cecectomized rats are useful in the study concerning digestamovement in the gut. Some of nutritional and physiological effectsof dietary fiber and fermentable food components are extinguishedby cecectomy. Some inverse results are obtained in the rats with orwithout 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 usefulexperimental animal, there is a limitation to use the cecectomizedrat as an experimental animal in the study of the function offermentable food materials. Further comparative studies are neededin the functions of the digestive tract between human and thececectomized rat for the strict qualification of the usefulness inhuman nutrition studies.

Key words: cecum, gut ferrnentation, digesta flow, cecectomizedrat