Abstract
BACKGROUND: Accumulating evidence indicates that the occurrence, development, and treatment of inflammatory bowel disease (IBD) are closely related to the intestinal microecology. However, whether Crohn's disease (CD) and Ulcerative colitis (UC) are characterized by distinct gut microbial signatures and associated disease phenotypes remains to be determined. The present study investigates the correlation between potential pathogenic or protective intestinal bacteria and the clinical pathological characteristics of patients with IBD. METHODS: A total of 274 tissue samples from patients with IBD, including 237 formalin-fixed paraffin-embedded (FFPE) samples and 37 fresh samples, were detected by qPCR for Enterotoxigenic Bacteroides fragilis, Klebsiella pneumoniae, Listeria monocytogenes, Akkermansia muciniphila, and Mycobacterium avium subspecies paratuberculosis. The study identified significant correlations between specific bacteria and clinical features such as age, disease location, disease behavior, and immunohistochemical markers. RESULTS: Among patients with CD, Enterotoxigenic Bacteroides fragilis colonization was associated with Epstein-Barr virus (EBV) infection, Ki-67 expression, disease behavior, and prognosis. Klebsiella pneumoniae colonization showed a significant association with EBV infection and lesion location. Listeria monocytogenes colonization was correlated with IgG4 levels and disease location. Moreover, as a potential probiotic, the colonization rate of Akkermansia muciniphila is significantly higher during the remission phase than in the active phase of CD. Notably, among patients with UC, these bacteria did not correlate well with clinical pathological characteristics. In addition, compared with healthy people, these bacteria in the feces of patients with CD and UC also exhibit different characteristics. CONCLUSIONS: These findings suggest that, compared with UC, certain specific gut bacteria, such as Enterotoxigenic Bacteroides fragilis, may play a more important role in the occurrence, development and prognosis of CD. In addition, different intestinal microbiota-based therapeutic strategies should be developed for CD and UC.