503 Small Intestinal Bacterial Overgrowth (SIBO) in Functional Dyspepsia (FD): Does Dyspeptic Symptom Pattern Make a Difference?

Abstract

INTRODUCTION: FD is a common gastrointestinal disorder with poorly understood pathophysiology. Patients with FD and SIBO frequently overlap symptomatically. The prevalence of SIBO in patients with FD is not well studied, particularly in relation to the predominant FD symptom profile. We aimed to evaluate the prevalence of SIBO diagnosed by glucose breath test (GBT) in patients with FD and compare the SIBO prevalence in FD subtypes - Postprandial Distress Syndrome (PDS), Epigastric Pain Syndrome (EPS) or both (PDS+EPS). METHODS: Retrospective, tertiary center, study of patients fulfilling Rome criteria for FD, who completed GBT (2018-2019). Demographics, history, medications, and GBT findings were reviewed. Patients with documented structural disease (eg. neoplasm) were excluded. GI symptoms (including mid upper abdominal pain or burning, early satiety and postprandial fullness) were prospectively collected from all patients at the time of their GBT. Based on these responses, patients were classified into: 1. FD-PDS, 2. FD-EPS and 3. FD-PDS+EPS. A priori variables associated with SIBO were analyzed including: presence of diabetes, GERD, and gastroparesis; history of small bowel surgery or gastric bypass; use of opioids or proton pump inhibitors. Prior to GBT, patients had low carbohydrate diet (2 days), no antibiotics (30 days) and no tobacco (12 hrs). Positive GBT for SIBO was defined by ≥20 ppm H2 increase over basal within 90 min and/or ≥10 ppm CH4 increase at any time. Statistical methods included chi-square and t test. RESULTS: 737 consecutive patients were studied (mean age=51.6±17.6 years, 70% female, 88% Caucasian, mean BMI=28.4±7.1). No differences in demographic or a priori SIBO-associated variables were found between the 3 subgroups of FD patients (P = NS). 31.4% of patients fulfilling criteria for FD had a GBT positive for SIBO. Individual gas (H2, CH4, or both) excretion responsible for a positive glucose HBT in each of the FD subgroups is shown on Table 1. There was no statistically significant difference in the prevalence of SIBO (by either H2, CH4 or both) between the three FD patient subtypes. There was borderline significant difference for slower H2 peak depicting a positive GBT in FD-PDS compared to FD-EPS and FD-EPS+PDS (83.8 vs. 70.7 vs. 65.7 minutes, P = 0.05). CONCLUSION: SIBO diagnosed by GBT is common in patients with FD regardless of the predominant symptomatic pattern. The prevalence of SIBO was similar in the three FD subtypes.