Prevalence of the pathobiont adherent‐invasive <scp><i>Escherichia coli</i></scp> and inflammatory bowel disease: a systematic review and meta‐analysis
Banafsheh Nadalian, Abbas Yadegar, Hamidreza Houri, Meysam Olfatifar, Shabnam Shahrokh, Hamid Asadzadeh Aghdaei, Hidekazu Suzuki, Mohammad Reza Zali
Abstract
BACKGROUND AND AIM: Escherichia coli pathobionts and particularly the adherent-invasive E. coli (AIEC) may play a putative role in initiating and maintaining the inflammatory process in the intestinal tissues of inflammatory bowel disease (IBD) patients, by providing stimulatory factors that trigger gut immune system activation. The aim of this study is to conduct a systematic review and meta-analysis to determine the prevalence of AIEC among patients with Crohn's disease (CD) and ulcerative colitis (UC). METHODS: Electronic databases were searched up to February 2020 for relevant publications reporting the prevalence of AIEC in IBD patients. The prevalence rate of AIEC among CD and UC patients, the odds ratio (OR) and 95% confidence interval (CI) were calculated compared to non-IBD controls. RESULTS: The final dataset included 12 studies, all investigating AIEC isolates from ileal/colonic specimens. The OR for prevalence of AIEC in CD patients was 3.27 (95% CI 1.79-5.9) compared with non-IBD controls. The overall pooled prevalence of AIEC among CD patients was 29% (95% CI 0.17-0.45), whereas this prevalence was calculated to be 9% (95% CI 0.03-0.19) in controls. Moreover, the prevalence of AIEC in UC subjects was calculated 12% (95% CI 0.01-0.34), while AIEC showed a prevalence of 5% (95% CI 0.0-0.17) among the controls. The OR for prevalence of AIEC in UC patients was 2.82 (95% CI 1.11-7.14) compared with controls. CONCLUSIONS: There is a substantial increase in the prevalence of AIEC in IBD patients compared with controls. This review supports the growing evidence that AIEC could be involved in both CD and UC pathogenesis.