Abstract
Intestinal putrefactive products appear to be harmful substances to the host. However, there are few good animal models with elevated production of intestinal putrefactive substances. Recently, an MES rat developing spontaneous eosinophilia with eosinophil-related inflammatory lesions especially in the gastrointestinal tract was introduced. In the present study, haematology, macropathology, composition of faecal flora and caecal concentration of putrefactive products of MES and normal rats at different ages were investigated. An apparent increase in blood leukocytes and eosinophils was observed in the MES rats at 10 weeks of age and became more severe with age. Polypoid lesions in the stomach and thickening of the intestinal walls were associated with the development of eosinophilia. At 18-19 weeks of age, the numbers of total bacteria, Bacteroidaceae, clostridia and lactobacilli and percentage of cultured bacteria to direct microscopic counts were significantly higher in the MES rats than in normal rats. The concentrations of caecal putrefactive products increased remarkably with age in the MES rats and were significantly higher than in normal rats at 18-19 weeks of age. As the abnormal intestinal environment was developed with age accompanying abnormal gastrointestinal structure, the MES rat may be a good model for studying the mechanism of production and methods of controlling intestinal putrefactive products accompanying aging and gastrointestinal disorders.