Short article: Risk of small intestinal bacterial overgrowth with chronic use of proton pump inhibitors in children

Background Some theorize that prolonged use of proton pump inhibitors (PPIs) may increase the risk of small intestinal bacterial overgrowth (SIBO). Chronic acid suppression and resultant hypochlorhydria may lead to an altered intraluminal environment, which, in turn, may promote the growth of bacteria in the small intestine. A handful of studies measured the risk of SIBO in adults taking PPIs and obtained mixed results; however, this risk has not been exclusively measured in children. Aim This study aimed to measure the risk of SIBO in children taking PPI versus those not taking PPI. Patients and methods This was a prospective cohort study. Evaluation of SIBO was performed using the glucose hydrogen breath test. Patients younger than 18 years of age taking a PPI longer than 6 months were compared with healthy control participants. After ingestion of glucose substrate, breath samples were obtained every 15 min for 2 h. An increase in breath hydrogen or methane above 12 ppm was considered diagnostic of SIBO. Results Overall, 83 participants were tested, of whom 56 were taking PPIs. SIBO was detected in five (8.9%) of the 56 participants taking PPI versus one (3.7%) of the 27 participants in the control group (P=0.359), with a relative risk of 2.4 (95% confidence interval: 0.29-19.6). Conclusion To our knowledge, this is the first study in the English literature measuring the risk of SIBO in children taking PPIs. Our results indicate a potential risk of SIBO in chronic PPI users; however, this is not statistically significant. This is an important finding as PPIs are readily prescribed for children and are often taken longer than 6 months' duration.