RESUMO
INTRODUCTION: Proton pump inhibitors could have an impact on the results of breath tests performed in patients with irritable bowel syndrome. This impact could be due to the development of small intestine bacterial overgrowth. OBJECTIVE: To compare the prevalence of fermentative profile alterations of irritable bowel syndrome patients exposed and not-exposed to proton pump inhibitor therapy. MATERIAL AND METHODS: Subjects with irritable bowel syndrome were enrolled. A validated questionnaire assessing symptom severity as well as proton pump inhibitor treatment was delivered. A lactulose breath test was undertaken by each enrolled subject. Fermentative profile (area under the curve of hydrogen excretion/time) was compared between proton pump inhibitors consumers and non-consumers. Furthermore, small intestine bacterial overgrowth prevalence was compared. RESULTS: Two hundred and twenty five patients were enrolled. No significant differences were found on the fermentative profile between groups [AUC mediana 3,776 (rango 2,124-5,571) vs 4,347 (rango 2,038-5,481), P = 0.3]. Small intestine bacterial overgrowth prevalence was similar as well [33% vs 27.5%]. These differences remained non-significant after adjusting for proton pump inhibitor dose and treatment time. Surprisingly, symptom score was significantly higher in those patients under proton pump inhibitor therapy [28.5 (23-26) vs 23 (15-29), P = 0.01]. CONCLUSION: Proton pump inhibitors have no significant influence on lactulose breath tests, regardless of the dosage and time of administration.