Research On The Incidence And Relevant Factors Of Small Intestinal Bacterial Overgrowth In Inflammatory Bowel Disease Patients

ObjectiveThe present study was aimed to evaluate the incidence of small intestinal bacterial overgrowth(SIBO)in inflammatory bowel disease(IBD)patients.Besides,to perform a retrospective analysis about the information of previous nasojejunal tube placement.Finally,we explored the relevant risk factors and predictors with SIBO incidence in IBD patients.MethodsWe included 67 ulcerative colitis(UC)and 111 Crohn’s disease(CD)inpatients in the Department of Gastroenterology and Hepatology of Nanjing University affliated Jinling Hospital from December 2016 to December 2017.In addition,49 age-and gender-matched healthy controls in the same period were enrolled.All participants were undergone the lactulose hydrogen-methane breath test(LHMBT).The level of blood inflammatory indicators,abdominal symptoms,IBD questionnaire(IBD-Q),and clinical disease activity were also evaluated on the day of admission.Endoscopic procedures were conducted in one week after LHMBT,and then evaluated the endoscopic disease activity.Demographic data,Montreal classification,therapeutics,information of previous intestinal surgery and nasojejunal tube placement were recorded for enrolled patients.Data were analyzed by Statistical Package for Social Sciences(SPSS)version 24.Student’s t-test was applied for continuous data if data with parametric distribution;otherwise,the Mann-Whitney U test would be performed.Chi-square(x2)test or Fisher’s exact test was used in the comparison between SIBO positive group and SIBO negative group.Factors included in a multivariate logistic regression model to explore the risk factors for SIBO incidence in UC and CD were those with statistical difference on univariate analysis.A two-tailed P-value<0.05 was considered to be statistically significant.Results1.Comparisons of the SIBO incidence among the three groups:The SIBO incidence in UC(28.4%vs 10.2%,)χ2=5.68,P=0.017)and CD patients(46.8%vs 10.2%,χ2=19.90,P<0.001)were significantly higher than healthy controls.Furthermore,SIBO incidence in CD patients was significantly higher as compared to UC(46.8%vs 28.4%,χ2=5.96,P=0.015).2.Factors associated with SIBO in UC patients:UC patients between SIBO positive group and SIBO negative group had no statistical significance in mean age,gender composition,levels of blood inflammatory indicators,scores of abdominal symptoms and IBD-Q.Additionally,clinical disease activity,previous colectomy,previous and current therapeutics were not significantly associated with SIBO incidence.SIBO positive rate were significantly higher in those patients that disease duration≥ 3 years(χ2=5.24,P=0.022),lesion involved extensive colon(χ2=4.73,P=0.039),stayed in endoscopically active disease(χ2=3.92,P=0.048).Results of multivariate logistic regression suggested that disease duration>3 years(OR=4.35,95%CI 1.32-14.39,P=0.016)and lesion involved extensive colon(OR=6.32,95%CI 1.23-32.62,P=0.028)were the independent risk factors of SIBO in UC.3.Factors associated with SIBO in CD patients:CD patients between SIBO positive group and SIBO negative group had no statistical significance in mean age,gender composition,disease courses,levels of blood inflammatory indicators,and scores of several abdominal symptoms(like abdominal pain,belch,diarrhea and flatus).Additionally,clinical disease activity,perianal lesion,history of intestinal surgery,previous and current therapeutics were not significantly associated with SIBO incidence.Median score of bloating and postprandial fullness in SIBO positive group were significantly higher as compared to SIBO negative group[0(0-5)vs 0(0-0),P=0.007;0(0-3)vs 0(0-0),P=0.046],while median IBD-Q showed a lower tendency[175(155-198)vs 189(171-202),P=0.016].In CD patients,SIBO positive rate was significantly higher in those patients that lesions involved small intestine(χ2=9.07,P=0.002),stenosis(χ2=12.01,P=0.001),stayed in endoscopically active disease(χ2=7.94,P=0.005),and previous nasojejunal tube placement(χ2=10.05,P=0.002).Results of multivariate logistic regression suggested that stenosis(OR=3.20,95%CI 1.24-8.27,P=0.016)and previous nasojejunal tube placement(OR=3.63,95%CI 1.30-10.14,P=0.014)were the independent risk factors of SIBO in CD,and postprandial fullness(OR=3.86,95%CI 1.12-13.28,P=0.03)was the independent predictor.Conclusions1.The SIBO incidence in IBD patients was significantly higher than healthy controls,especially in CD patients.2.SIBO in UC patients were associated with disease duration≥ 3 years,lesion involved extensive colon,and endoscopically active disease.The independent risk factors of SIBO in UC were disease duration≥ 3 years and lesion involved extensive colon.3.SIBO in CD patients were associated with endoscopically active disease,lesions involved small intestine,stenosis,previous nasojejunal tube placement,bloating,postprandial fullness,and IBD-Q.The independent risk factors of SIBO in CD were stenosis and previous nasojejunal tube placement,while the independent predictor was postprandial fullness.