The effects of a weakly acidic meal on gastric buffering and postprandial gastro-oesophageal reflux
Article first published online: 5 JUL 2011
© 2011 Blackwell Publishing Ltd
Alimentary Pharmacology & Therapeutics
Volume 34, Issue 5, pages 568–575, September 2011
How to Cite
Ravi, K., Francis, D. L., See, J. A., Geno, D. M. and Katzka, D. A. (2011), The effects of a weakly acidic meal on gastric buffering and postprandial gastro-oesophageal reflux. Alimentary Pharmacology & Therapeutics, 34: 568–575. doi: 10.1111/j.1365-2036.2011.04761.x
- Issue published online: 2 AUG 2011
- Article first published online: 5 JUL 2011
- Publication data Submitted 17 May 2011 First decision 12 June 2011 Resubmitted 16 June 2011 Accepted 18 June 2011 EV Pub Online 5 July 2011
Aliment Pharmacol Ther 2011; 34: 568–575
Background Exclusion of the meal during ambulatory pH monitoring presumes that a meal completely buffers gastric acid and reflux of acidic food content cannot be distinguished from gastric acid. However, the ability of a meal to completely buffer gastric acid remains unclear.
Aim To determine the effect of a weakly acid meal on gastric buffering and oesophageal acid exposure.
Methods Patients undergoing multichannel intraluminal impedance pH studies were given a standard weakly acidic meal (pH = 5.9). Gastric and oesophageal pH was measured during the meal and in 15 min intervals for 2 h postprandially.
Results The study included 30 patients, with pathological acid reflux detected in 18 patients. Complete gastric buffering occurred in seven patients (23%) and was lost in all patients within 75 min of the meal. Oesophageal acid was detected in 33% of patients within 30 min of the meal and 81% of patients during the 2 h postprandial period. Postprandial oesophageal acid exposure was greater in patients with pathological acid reflux (9 ± 2.7% vs. 1.7 ± 0.8%P = 0.05) with a trend towards more incomplete gastric acid buffering and significant differences when measuring weak acid reflux (pH 4–5). Acid reflux rarely occurred in the absence of gastric acid, with gastric acid present in 74 of 79 (94%) fifteen minute postprandial intervals with acid reflux.
Conclusions The ability of a meal to buffer gastric acid is poor. Early postprandial oesophageal acid reflux occurs in a substantial proportion of patients. Addition of a weakly acidic or pH neutral meal to ambulatory pH monitoring may unmask early postprandial acid reflux and provide data on gastric acid buffering.