Factors That Affect Prevalence of Small Intestinal Bacterial Overgrowth in Chronic Pancreatitis: A Systematic Review, Meta-Analysis, and Meta-Regression

Small intestinal bacterial overgrowth (SIBO) can complicate chronic pancreatitis (CP) and interfere with management. Its predisposing factors in CP and treatment response are unknown. In this review, we evaluated factors affecting disease burden. METHODS: A computerized search of PubMed and EMBASE databases from inception through May 2019 was done for studies correlating SIBO with CP. Studies were screened, and relevant data were extracted and analyzed. Pooled prevalence, odds ratio (OR), and meta-regression were performed using the random effects model as classically described by Borenstein et al. (2009). SIBO's relation to diabetes mellitus (DM), pancreatic exocrine insufficiency (PEI), narcotic use, and proton-pump inhibitor use was investigated. Treatment response was pooled across studies. P value < 0.05 was considered significant. RESULTS: In 13 studies containing 518 patients with CP, SIBO prevalence was 38.6% (95% confidence interval [CI] 25.5–53.5). OR for SIBO in CP vs controls was 5.58 (95% CI 2.26–13.75). Meta-regression showed that PEI and the diagnostic test used were able to explain 54% and 43% of the variance in SIBO prevalence across studies, respectively. DM and PEI were associated with increased SIBO in CP with OR (2.1, 95% CI 1.2–3.5) and OR (2.5, 95% CI 1.3–4.8), respectively. Symptomatic improvement was reported in 76% of patients after SIBO treatment. DISCUSSION: SIBO complicates 38% of CP with OR of 5.58 indicating a predisposition for this condition. PEI correlates with SIBO in CP and might play a role in pathophysiology. DM and PEI are associated with increased SIBO in CP. Treatment of SIBO may lead to symptomatic improvement.