Assessment of combined bile acid and pH profiles using an automated sampling device in gastro-oesophageal reflux disease

Abstract

Background: Bile acid reflux is an important component of duodenogastro-oesophageal reflux but there is no effective method of quantifying it. The contribution of bile acids to oesophageal pH is unknown. Methods: Oesophageal aspirates were collected over 15 h using a new automated suction device and pH was monitored in ten asymptomatic volunteers (group 1) and 30 patients with reflux oesophagitis (group 2, minimal mucosal injury; group 3, erosive oesophagitis; group 4, stricture or Barrett's oesophagus). Bile acid assay was performed by high-performance liquid chromatography. Results: The concentration of bile acids was significantly higher in group 3 (median (interquartile range) 124 (50–301) µmol/l) and group 4 (181 (85–591) µmol/l) compared with group 1 (0 µmol/l) and group 2 (14 (0–100) µmol/l). Patients in groups 3 and 4 also had significantly greater DeMeester acid scores. Combined bile acid and oesophageal acid reflux was observed in eight of ten patients with stricture or Barrett's oesophagus. There was no correlation between total bile acid concentration and oesophageal acid or alkaline exposure. Conclusion: This study supports the theory of toxic synergism between acid and bile acids in reflux oesophagitis. Bile acids may contribute to the pathogenesis of Barrett's metaplasia.