ABSTRACT
Background/Aims@#Crosstalk between the gut microbiota and bile acid plays an important role in the pathogenesis of gastrointestinal disorders. We investigated the relationship between microbial structure and bile acid metabolism in the ileal mucosa of Crohn’s disease (CD). @*Methods@#Twelve non-CD controls and 38 CD patients in clinical remission were enrolled. Samples were collected from the distal ileum under balloon-assisted enteroscopy. Bile acid composition was analyzed by liquid chromatography-mass spectrometry. The gut microbiota was analyzed by 16S rRNA gene sequencing. @*Results@#The Shannon evenness index was significantly lower in endoscopically active lesions than in non-CD controls. β-Diversity, evaluated by the UniFrac metric, revealed a significant difference between the active lesions and non-CD controls (P=0.039). The relative abundance of Escherichia was significantly higher and that of Faecalibacterium and Roseburia was significantly lower in CD samples than in non-CD controls. The increased abundance of Escherichia was more prominent in active lesions than in inactive lesions. The proportion of conjugated bile acids was significantly higher in CD patients than in non-CD controls, but there was no difference in the proportion of primary or secondary bile acids. The genera Escherichia and Lactobacillus were positively correlated with the proportion of conjugated bile acids. On the other hand, Roseburia, Intestinibacter, and Faecalibacterium were negatively correlated with the proportion of conjugated bile acids. @*Conclusions@#Mucosa-associated dysbiosis and the alteration of bile acid composition were identified in the ileum of CD patients. These may play a role in the pathophysiology of ileal lesions in CD patients.
ABSTRACT
Background/Aims@#We retrospectively analyzed Crohn’s disease (CD) patients with small intestinal strictures who underwent single-balloon enteroscopy (SBE) to ascertain whether prototype SBEs with a passive bending mechanism and high force transmission insertion tube had better insertability in the small intestine than a conventional SBE. @*Methods@#Among 253 CD patients who underwent SBE, we identified 94 CD patients who had undergone attempted endoscopic balloon dilatation (EBD) for small intestinal stenosis for inclusion in this study. We analyzed whether the type of scope used for their initial procedure affected the cumulative surgery-free rate. For the insertability analysis, patients who underwent SBE at least twice were divided into 3 groups according to the type of scope used: conventional SBE only, prototype SBE only, and both conventional and prototype SBEs. For each group, depth of insertion, procedure time, and number of EBDs were compared in the same patient at different time points. @*Results@#The success rate of EBD was 88.3%. The 5- and 10-year cumulative surgery-free rate was 75.7% and 72.8%, respectively. Cox regression analysis indicated that the factors contributing to surgery were long stricture (≥2 cm), EBD failure, and elevated Crohn’s Disease Activity Index, but not the type of scope used for EBD. The prototype SBEs significantly improved the depth of insertion (P=0.03, Wilcoxon’s signed-rank test). @*Conclusions@#In CD patients with small intestinal stenosis, the prototype SBEs with a passive bending mechanism and high force transmission insertion tube did not improve long-term EBD outcome but did improve deep insertability. (Clinical Trial Registration No. UMIN000037102)