Features of the mucous barrier in functional bowel diseases and ulcerative colitis

Abstract

Background. The intestinal mucosal barrier may change under the influence of exogenous and endogenous factors. Changes in its physical and chemical characteristics are observed in patients with gastrointestinal diseases, such as irritable bowel syndrome, ulcerative colitis, Crohn’s disease, and with other pathologies, such as diabetes mellitus, food allergies, rheumatoid arthritis, etc. Also, the permeability of the intestinal wall was influenced by tight junctions, which are weakened due to eating disorders, psycho-emotional factors, and chemical agents. The purpose of the study was evaluating of changes in the mucosal barrier in patients with functional and inflammatory bowel diseases. Materials and methods. 270 patients with different subtypes of irritable bowel syndrome and 218 patients with ulcerative colitis were examined. Colonoscopy followed by a morphological assessment of biopsy specimens and immunohistochemical studies using markers of claudin 1 and 7, mucins 1, 2, 3, 4, 5AC, and trefoil factors 1–3 was performed in all patients. Results. A decrease in the level of tight junction proteins called claudins was observed in patients with functional bowel disease. Patients with irritable bowel syndrome associated with diarrhea had a lower level of claudin-1 only, while patients with mixed form had also a lower level of claudin-7. A decrease in the level of both secretory and membrane-bound mucins and an increase in the level of the trefoil factors were observed at the same time among the patients with ulcerative colitis which may indicate a dysregulation and a violation of the protective function of mucus. Conclusions. The pathogenesis of a violation of the protective function of the mucosa of functional and inflammatory bowel disease is different, which may determine approaches to the treatment of patients with such pathologies.