Toxic bile acids in gastro-oesophageal reflux disease: influenceof gastric acidity

摘要

BACKGROUND—Bile acid toxicity has been shown in the gastric, colonic, and hepatic tissues; the effect on oesophageal mucosa is less well known.
AIMS—To determine the spectrum of bile acids refluxing in patients with gastro-oesophageal reflux disease and its relation to oesophageal pH using a new technique of combined oesophageal aspiration and pH monitoring.
METHODS—Ten asymptomatic subjects and 30 patients with symptoms of gastro-oesophageal reflux disease (minimal mucosal injury, erosive oesophagitis (grade 2 or 3 Savary-Miller), Barrett's oesophagus/stricture; n=10 in each group) underwent 15 hour continuous oesophageal aspiration with simultaneous pH monitoring. Bile acid assay of the oesophageal samples was performed using modified high performance liquid chromatography.
RESULTS—The peak bile acid concentration and DeMeester acid scores were significantly higher in the patients with oesophagitis (median bile acid concentration 124 µmol/l; acid score 20.2) and Barrett's oesophagus/stricture (181 µmol/l; 43.3) than patients with minimal injury (14 µmol/l; 12.5) or controls (0 µmol/l; 11.1). The predominant bile acids detectedwere cholic, taurocholic, and glycocholic acids but there was asignificantly greater proportion of secondary bile acids, deoxycholicand taurodeoxycholic acids, in patients with erosive oesophagitis andBarrett's oesophagus/stricture. Although bile acid reflux episodesoccurred at variable pH, a temporal relation existed between reflux oftaurine conjugates and oesophageal acid exposure(r=0.58, p=0.009).
CONCLUSION—Toxic secondary bileacid fractions have been detected in patients with extensive mucosaldamage. Mixed reflux is more harmful than acid reflux alone withpossible toxic synergism existing between the taurine conjugates and acid.

Keywords:bile acids; reflux oesophagitis; Barrett'soesophagus