Objectives: The purposes of this report were to examine whether or not a positive bile acid breath test in cirrhotic patient was associated with bacterial overgrowth in the upper small intestine, to verify that these bacteria have deconjugation ability, and, in addition, to elucidate whether or not changes in the gastric pH are related to bacterial overgrowth.
Methods: Twenty-seven patients with liver cirrhosis were tested by breath analysis technique using glycine-1-14C-labeled glycocholate. Jejunal fluids were aspirated through a double-lumen tube with a rubber cover on the tip. Anaerobes and aerobes were isolated and identified. After culturing, we used thin layer chromatography to determine whether each bacteria had the ability to deconjugate bile salts.
Results: Expired breath samples from seven of 27 patients with liver cirrhosis showed a marked increase of 14CO2-specific activity. Bacterial overgrowth was found in the jejunal fluid of these patients. Administration of chloramphenicol to the seven patients reduced 14CO2 specific activity significantly. The majority of the species identified deconjugated bile acids. Seventeen healthy control subjects showed no increase in CO2 excretion, and 16 of the 17 had no bacteria isolated from jejunal fluid. The relationship between 14CO2 specific activity of expired breath samples and gastric pH was also tested in the cirrhotic patients. There was a relatively good correlation (n = 27, r = 0.87, p < 0.05) between 14CO2 activity and gastric pH.
Conclusion: We conclude that some patients with liver cirrhosis have bacterial overgrowth in the proximal small intestine that contains species that can deconjugate bile salts, and that the bacterial overgrowth is probably associated with the shift to alkaline pH in gastric juice.