Breath hydrogen and methane are associated with intestinal symptoms in patients with chronic pancreatitis

Backgrounds The bacterial overgrowth might be associated with chronic pancreatitis. This study was to evaluate the prevalence and characteristics of small intestinal bacterial overgrowth (SIBO) in patients with chronic pancreatitis. Methods 36 patients with chronic pancreatitis and 49 healthy controls undergoing the hydrogen (H₂)-methane (CH₄) lactulose breath test (LBT) were reviewed. The LBT positivity (+) indicating the presence of SIBO, gas types, bowel symptom questionnaire, laboratory and radiologic results were surveyed. The LBT+ was (1) an increase in the breath H₂ (≥20 ppm) or CH₄ (≥10 ppm) over the baseline or (2) a baseline H₂ (≥20 ppm) or CH₄ (≥10 ppm) within 90 min after lactulose load. Results LBT+ was significantly higher in the patients (17/36) than in controls (13/49) (47.2% vs. 26.5%, P < 0.05). During LBT, the H₂ levels between 0 and 105 min were significantly higher in patients than in controls. Among LBT+ patients, 11 (64.7%), 1 (5.9%), 5 (29.4%) were in the LBT (H₂)+, (CH₄)+, (mixed)+ groups, respectively. The LBT+ group had significantly higher scores of flatus than those of the LBT- group. Considering the subtypes of LBT, the LBT (mixed)+ group had higher symptom scores of significance or tendency in hard stool, strain, urgency, and flatus than LBT- group The laboratory and radiologic features were not significantly different between LBT+ and LBT- groups. Conclusions SIBO is common in patients in chronic pancreatitis. Especially, excretions of mixed H₂ and CH₄ appear to be related with deterioration of intestinal symptoms.