The Effect of Immunoregulatory Bacteria on the Transcriptional Activity of Foxp3 and Roryt Genes in the Gutassociated Lymphoid Tissue With Salmonellainduced Inflammation in the Presence of Vancomycin and ВаCteroides Fragilis

Background and objectives: intestinal microbiota is involved in the development and maintenance of immune homeostasis.this study was conducted to investigate the levels of key immunoregulatory bacteria in the intestinal wall-associatedmicroflora and its effect on the transcriptional activity of the foxp3 and roryt genes in the gut-associated lymphoid tissue(galt) of rats with salmonella-induced inflammation, both untreated and treated with vancomycin and bacteroides fragilis.materials and methods: to determine the levels of immunoregulatory bacteria in galt of rats q-pcr was used to identifythem by species-specific 16s rdna genes. transcriptional activity of foxp3 and roryt genes was determined using q-pcrwith reverse transcription.results: in animals treated with both vancomycin and salmonella, the levels of segmented filamentous bacteria (sfb) increasedwhile akkermansia muciniphila and faecalibacterium prausnitzii decreased. in rats that received pretreatment withvancomycin and then were infected with s. enteritidis and s. typhimurium, the levels of sfb increased, and the number ofbacteroides-prevotela group, a. muciniphila, clostridium spp. clusters xiv, iv, and f. prausnitzii significantly decreased,decreasing foxp3 and increasing rorγt mrna expression. administration of b. fragilis to animals treated with s. enteritidisor s. typhimurium and pre-treated with vancomycin caused a decrease in sfb and rorγt mrna levels and conversely,increased the numbers of the bacteroides-prevotela group, clostridium spp. clusters xiv, iv, a. muciniphila, f. prausnitziiand foxp3 gene expression in galt.conclusion: our results suggest that the commensal microorganism b. fragilis may provide a protective role against thedevelopment of experimental colitis, which has to be taken into consideration for further clarification of the effective therapeuticstrategy of inflammatory bowel diseases, irritable bowel syndrome and necrotising colitis.