Small Intestinal Bacterial Overgrowth in Gastroparesis

To determine symptoms of small intestinal bacterial overgrowth (SIBO) in gastroparesis patients.

Patients undergoing LBT (lactulose breath test) for evaluation of SIBO were included. LBT was considered positive on the basis of three conventional criteria: (1) hydrogen level increase >20 ppm above baseline by 90 min (H2@90min); (2) dual hydrogen peaks (>10 ppm increase over baseline before second peak >20 ppm (DPHBT); and (3) breath methane increase of >20 ppm above baseline by 90 min. Results of gastric emptying scintigraphy (GES) were recorded. Patients completed the Patient Assessment of Upper Gastrointestinal Disorders-Symptom Severity Index.

Of 740 patients who underwent LBT from December 2009 to August 2011, 471 underwent GES, with 201 having delayed GES. Of patients with delayed GES who underwent LBT 87 % were female, 23 % diabetic, 49 % used gastric acid suppressants, 29 % used opiate analgesics, 35 % used pro-motility medications, and 27 % had a history of gastrointestinal surgery. Overall, 79 (39 %) patients with gastroparesis had evidence of SIBO by LBT: 30 (15 %) had positive H2@90min, 53 (26 %) positive DPHBT, and 6 (3 %) positive breath methane test. In gastroparesis patients with positive H2@90min, there was increased severity of bloating (3.80 ± 0.20 vs 3.29 ± 0.12; P = 0.02), early satiety (3.57 ± 0.27 vs 3.05 ± 0.13; P = 0.045), and postprandial fullness (4.20 ± 0.18 vs 3.52 ± 0.12; P < 0.01) compared with negative H2@90min patients. No significant difference in symptom severity was seen between positive and negative DPHBT gastroparesis patients.

In our cohort, 39 % of gastroparesis patients tested positive for SIBO by LBT. Positive H2@90min testing by LBT was associated with increased symptoms of bloating and excessive fullness during and after meals.