New technique for analysing conjugated bile acids in gastric juice.

A new technique of high performance liquid chromatography (HPLC) was developed for the analysis of conjugated bile acids in gastric juice. The assay is rapid, sensitive, and highly specific for bile acid conjugates over the range 30-10,000 mumol/l and is not affected by the presence of food. Ten patients with a variety of common upper gastrointestinal disorders underwent continuous gastric aspiration for 16 hours, including a fasting, post-prandial, and nocturnal period, and aliquots of aspirates were analysed every two hours by the HPLC technique for the six most prevalent bile acid conjugates present in human hepatic bile. Intragastric bile acid concentrations were lowest in the post-prandial period and highest in the early hours of the morning. Conjugated bile acid proportions, or profiles, varied considerably from patient to patient, but tended to remain uniform over time in individual patients. It is concluded that HPLC is superior to enzymatic techniques for the analysis of conjugated bile acids in the upper gastrointestinal tract.