PPI e SIBO: Facts and Myths

PPI e SIBO: Facts and Myths – BACKGROUND:

Proton Pump Inhibitors (PPI) can cause diarrhea, enteric infections and alter gastrointestinal population by suppressing the gastric acid barrier (1).

Glucose Hydrogen Breath Test (GHBT) is sensitive enough and highly specific for small intestinal bacterial overgrowth (SIBO) diagnosis (2). Although it has been demonstrated that SIBO prevalence is significantly higher in patients treated with PPI than in controls (3), some authors, on the ground of retrospective studies (4) maintain that a causal link between PPI use and SIBO remains to be demonstrated. In a recent study we found that 50% of 200 patients treated with PPI for at least 1 year were affected by SIBO vs 24%of 200 patients with irritable bowel syndrome (p<.001). Eradication of SIBO was achieved after Rifaximin treatment (400 mg 3 times per day for 2 wks) in 87% of PPI-related SIBO and in 91% of IBS-related SIBO). Our aim is to obtain further information by studying the out-come of these same patients, after SIBO eradication.


prospectively verify the outcome of 1) patients eradicated from PPI-related SIBO in relation with the discontinuation or continuation of PPI medication and 2) patients with IBS eradicated from SIBO, in relation with or without subsequent medication with PPI.


GHBTs were offered to 125 patients 1 year after eradication from SIBO (87 from PPI group, “A”; 45 from IBS group, “B”). Each patient was given a symptoms questionnaire.


Out of 87 patients of group A, 4 were lost at 1-year follow-up: 38 discontinued PPI treatment and 45 continued it. 37 out of 38 discontinuing PPI treatment (97%) and 5 out of 45 continuing PPI treatment (11%) were free from SIBO (P< .001). Out of 45 patients of group B 3 were lost at 1-year follow-up: 26 out of 28 patients not assuming PPI (93%) and 5 out of 14 assuming PPI (36%) were free from SIBO (P< .001). 42 out of 47 patients with SIBO were eradicated following therapy with Rifaximin 1200 mg/day for 2 wks (89%).


A previous our study demonstrated that SIBO occurs significantly more frequently among PPI users than controls (3). The present study shows that SIBO-free patients are significantly more frequent in PPI-discontinuing than in PPI-continuing group. In IBS group, SIBO-free patients are significantly more frequent in PPI-free group than in PPI-treated group. In our prospective studies, SIBO-PPI association seems to be linked by a causal factor, while the same cannot be claimed by retrospective studies (4). We think that clinicians have to be aware of these facts in order to avoid myths and prompt preventive management or therapeutic measures.


1)Sanduleanu S, Jonkers D, De Bruine A et al. Non-Helicobacter pylori bacterial flora during acid suppressive therapy: differential findings in gastric juice and gastric mucosa. Aliment Pharmacol Ther 2001;15:379-388.

2)Ghoshal UC, Ghoshal U, Das K et al. Utility of hydrogen breath tests in diagnosis of small intestinal bacterial overgrowth in malabsorption syndrome and its relationship with oro-cecal transit time. Indian J Gastroenterol 2006; 25:6-10.

3)Lombardo L, Foti M, Ruggia O, et al. Increased incidence of small intestinal bacterial overgrowth during proton pump inhibitor therapy. Clin Gastroenterol Hepatol 2010;8:504-8.

4)Ratuapli SK, Ellington TG O’Neill MT et al. Proton pump inhibitor therapy does not predispose to small intestinal bacterial overgrowth. Am J Gastroenterol 2012;107:730-5.