Thymol in Different Parts of the Rabbit Intestinal Tract: Its Effect on Intestinal Microbiota, Morphometry and Immunoglobulin A

The positive effect of thymol on gut health largely depends on its absorption from the intestinal tract and its biotransformation processes in the intestinal wall. A total of 32 rabbits were randomly divided at 35 days of age into a control (CG) and an experimental group (EG) that received thymol at 250 mg/kg feed. Thymol concentration was significantly higher in the caecum than in the ileum (p < 0.05), which is likely associated with caecotrophy and reduced enzymatic activity in the distal segments of the small intestine. Coliform bacteria (p = 0.0095) and lactic acid bacteria (LAB; p = 0.0002), Staphylococcus spp. (p = 0.0002), and Enterococcus spp. (p = 0.0002) in the duodenum; LAB (p = 0.0003) and Enterococcus spp. (p = 0.0002) in the ileum; and other Enterobacteriaceae (p = 0.0002) and LAB (p = 0.0068) in the caecum were significantly higher in the EG. Despite the significantly lower thymol concentration in the ileum compared to the caecum, the beneficial LAB was positively affected. A decrease in immunoglobulin A in all parts of the intestinal tract except the colon was a result of the modulation of mucosal immunity. Thymol at this concentration modulated the gut ecosystem without disrupting its beneficial components, thereby helping maintain intestinal homeostasis.

Klinik Hietzing
Institute of Animal Physiology of the Slovak Academy of Sciences
National Agricultural and Food Centre