Studies on the influence of Candida fungal colonization on the healing process of inflammatory lesions in the colon in rat animal model

: Present-day methods of successful treatment of inflammatory bowel diseases (IBD) result from a better understanding of their pathophysiology due to advances in preclinical studies in this area of knowledge. Until recently microbiological studies have been focused on the bacterial aspects in pathogenesis of GI disorders, however in the last years an interest in the presence of fungi in the gastrointestinal tract has also increased. In this study using an animal model of ulcerative colitis, the impact of fungal colonization of the colon on the intensity of inflammatory changes in the colonic mucosa and the course of their healing was carried out. The macroscopic and microscopic criteria relating to the changes of weight of examined fragments of the colon were evaluated while assessing differences between groups tested. The intensity of intestinal inflammatory changes was determined by assessment of such parameters, as colonic blood flow (CBF), the level of MPO as a marker of colonic neutrophil infiltration intensity and the plasma levels of IL-1beta; and TNF-alpha concentrations. Results at the 3rd day after TNBS rectal administration revealed an increase of weight of isolated segments of inflammed colon, a decrease of CBF and the 4-5 fold increase of plasma MPO activity. Candida colonization of colon mucosa of rats delayed healing of colonic ulcers, induced by TNBS and this was associated with the increased expression of plasma IL-1beta and TNF-alpha levels. Administration of antifungal (fluconazole) or probiotic (Lacidofil) treatment to C. albicans infected rats exerted favorable effect on healing of inflammatory changes in the colon because the area of ulcerations in groups of rats treated with fluconazole or Lacidofil was significantly smaller in comparison with those inoculated with Candida solution only. Administration of fluconazole or Lacidofil significantly decreased the weight of colon segments, the MPO activity and the plasma IL-1beta and TNF-alpha levels, as compared with respective values in the group receiving Candida only. The results of our studies indicate the deteriorating influence of Candida on the healing process of inflamed colon in the animal model of ulcerative colitis. Concomitant therapy with probiotic or antifungal treatment improved healing of colonic lesions, decreased the weight of inflamed colonic tissue and also attenuated the MPO activity and plasma proinflammatory cytokines IL-1beta and TNF-alpha levels.