A Preliminary Study On The Involvement Of CBS-H₂S Signal Pathway In The Irritable Bowel Syndrome

Background and AimAt present,the etiology and pathogenesis of Irritable Bowel Syndrome(IBS)are not clear.The imbalance of intestinal flora and increased visceral sensitivity may be closely related to the occurrence and development of IBS.Our previous study showed that CBS-H2S signaling pathway is involved in visceral hyperalgesia in a rat model of IBS.In this study,we observed the concentration of Hydrogen Sulfide(H2S)in feces,detected the expression of Cystathionine-?-synthase(CBS)in colonic mucosa,and analyzed the structure of intestinal flora in feces of patients with IBS.The purpose of present study was to provide experimental basis for elucidating the pathogenesis of IBS mediated by CBS-H2S signal system.Methods1.The fecal samples of 8 IBS patients and 8 healthy volunteers in the same period were collected,and the concentration of H2S in the stool samples of the two groups was determined by deproteinization method.2.Pearson correlation was used to analyze the relationship between the concentration of H2S in feces and the symptom score of patients with IBS.3.Colonic mucosal tissues of 8 patients with IBS(IBS group)and 8 healthy volunteers(CON group)were obtained under colonoscopy.The expression of CBS in colonic mucosa was detected by western blotting method.4.The fecal samples of 11 IBS patients and 11 healthy volunteers in the same period were collected,and the 16S rRNA sequencing technique was used to detect and analyze the changes of intestinal flora in the feces of patients with IBS and healthy volunteers.Results1.The concentration of H2S in feces of patients in IBS group was increased.The concentrations of H2S in feces of IBS group and CON group were 223.72±52.69 ?M and 89.69±22.49 ?M,respectively(***P<0.001).2.Pearson correlation results showed that there was a positive correlation between the concentration of H2S in feces and the symptom score of IBS patients,and the correlation coefficient was 0.979(***P<0.001).3.The expression of CBS in colonic mucosa of patients with IBS was markedly increased.The relative expression of CBS in IBS group and CON group was 0.86±0.07and 0.47±0.04,respectively(***P<0.001).4.The results of intestinal flora detection showed that the diversity of intestinal flora in IBS group was increased,and the abundance proportion of Clostridium in IBS group was significantly higher than that in CON group(*P<0.05).Other H2S-producing bacteria in feces of IBS patients were significantly higher than those in CON group.ConclusionsThe increased concentration of H2S in feces,the upregulation of CBS expression in colonic mucosa and the increase in the number of H2S-producing bacteria in patients with IBS suggest that CBS-H2S may play a role in the pathogenesis of IBS.