[The effects of continuous proton pump inhibitor therapy on small intestinal bacterial overgrowth in elderly]

Objective: Long-term proton pump inhibitor(PPI) therapy may increase the risk of small intestinal bacterial overgrowth(SIBO). Few studies on the effect of on-demand and continuous PPI therapy are available in elderly. To investigate the prevalence of SIBO and the effect of on-demand and continuous PPI therapy on SIBO in elderly. Methods: A total of 200 elderly outpatients admitted to Department of Gastroenterology at the Second Medical Center of PLA General Hospital were enrolled and divided into 3 groups: continuous PPI group, on-demand PPI group and control group. SIBO was diagnosed according to methane and hydrogen lactulose breath test (LBT).The prevalence of SIBO in the 3 groups was analyzed. Results: The prevalence of SIBO was 71.5% in 200 elderly. PPI therapy and diabetes mellitus (DM) were independent risk factors for SIBO. The prevalence of SIBO was 77.1% (108/140) in elderly who underwent long-term PPI therapy and 58.3% (35/60) in those without PPI therapy (P<0.01).The prevalence of SIBO was significantly higher in continuous PPI therapy group than that in on-demand PPI group and control group(88.6% vs. 65.7% and 58.3%, all P<0.01).However, no significant difference was found in the prevalence of SIBO between on-demand PPI group and control group (P>0.05). In elderly who underwent long-term PPI therapy, the prevalence of SIBO increased significantly if administration time was longer than 61 months. Conclusions: SIBO usually occurs in elderly patients who receive continuous PPI rather than on-demand use. If elderly require long-term PPI therapy, on demand administration is suggested as long as primary diseases are properly treated.