Prevalence of small intestine bacterial overgrowth diagnosed by quantitative culture of intestinal aspirate in celiac disease.

Background And Aim: A recent study using lactulose hydrogen-breath testing suggests that small intestine bacterial overgrowth (SIBO) is a common cause of nonresponsive celiac disease (CD). The prevalence of SIBO in CD diagnosed by quantitative culture of intestinal aspirate is unknown. The aim of this study is to evaluate the prevalence and significance of SIBO in CD based on the results of quantitative culture of intestinal aspirate.

Methods: We studied patients with CD in whom culture of intestinal aspirate was evaluated for the presence of anaerobes and aerobes. Bacterial overgrowth was diagnosed if culture demonstrated >10 colony forming units/mL. The causes of nonresponsive CD were investigated.

Results: We included 149 biopsy-confirmed CD patients. The intestinal aspirate was collected in 79 (53%) patients with nonresponsive CD, 47 (32%) as initial work-up for malabsorption, and in 23 (15%) asymptomatic treated CD. SIBO was diagnosed in 14 (9.3%). Nine (11%) with nonresponsive CD, 5 (11%) at initial work-up for malabsorption, and 0 in asymptomatic treated CD. Patients with a positive culture had evidence of worse malabsorption. A coexistent disorder was found in 67% of patients with both nonresponsive CD and bacterial overgrowth.

Conclusions: The prevalence of SIBO diagnosed by quantitative culture of intestinal aspirate was 9.3% in patients with CD. Patients with symptomatic treated or untreated CD were affected. SIBO may coexist with other disorders associated with nonresponsive CD.