Intestinal bacterial overgrowth during chronic pancreatitis

The presence of an intestinal bacterial overgrowth (IBO) in patients with pancreatic insufficiency has been recently suggested to justify the worsening of their clinical conditions despite pancreatic enzyme supplementation.

The purposes of this study were (a) to verify IBO frequency in patients with pancreatic insufficiency owing to chronic pancreatitis and (b) to evaluate the effect of chronic administration of a non-absorbable antibiotic, Rifaximin, in reducing IBO frequency and influencing the clinical picture of the disease.

Thirty-five patients with pancreatic insufficiency owing to chronic pancreatitis and 61 gastro-resected patients without pancreatic disease were studied. The presence of IBO was tested in both groups of patients using the hydrogen breath test with glucose. Chronic pancreatitis patients were subsequently treated with Rifaximin, 400 mg t.i.d for seven consecutive days each month for three months.

A positive hydrogen breath test was present in 12 out of 35 (34%) chronic pancreatitis patients and in 13 out 61 (21%) controls (p < 0.002). In chronic pancreatitis patients an IBO was most likely to be present in the presence of a high ethanol intake, pancreatic microcalcifications, concomitant gallstones, diarrhoea and a history of gastric resection. In all patients with IBO, Rifaximin administration normalised the hydrogen breath test and reduced symptoms.

IBO is frequent in patients with pancreatic insufficiency, particularly in those with a history of gastroduodenal surgery. Treatment with Rifaximin reduces IBO frequency and improves symptoms.