Influence of Escherichia coli infection on intestinal mucosal barrier integrity of germ-free piglets

Aims: We focused on investigating the influence of Escherichia coli (E. coli) on the intestinal barrier.Material and methods: We studied changes in the distribution and secretory activities of goblet cells and enteroendocrine cells (EECs), as well as changes in the population of mast cells (MCs) in the jejunal and colonic mucosa of germ-free (GF) piglets as a healthy control group and GF piglets whose intestines were colonised with E. coli bacteria on day 5.Key findings: The results suggest that the colon of GF piglets is more resistant and less prone to coliform bacterial infection compared to the jejunum. This can be confirmed by a lower degree of histopathological injury index as well as an improvement of the morphometric parameters of the colonic mucosa, together with a significantly increased (p < 0.05) expression of MUC1/EMA, and ZO-3. We also observed a significant decrease in the population of activated MCs (p < 0.001) and EECs (p < 0.001). These findings may indicate a rapid response and better preparation of the intestinal barrier for possible pathological attacks and the subsequent development of mucosal lesions during the development and progression of the intestinal diseases.Significance: To date, gut-targeted therapeutic approaches that can modulate bacterial translocation and chronic inflammation are still in their infancy but represent one of the most promising areas of research for the development of new effective treatments or clinical strategies in the future. Therefore, a better understanding of these processes can significantly contribute to the development of these targeted strategies for disease prevention and treatment.