Physiological belching during impedance-pH monitoring: a meal with Coca-Cola provokes a prompt gastroesophageal reaction with increased prandial belching.

OBJECTIVES

To assess the belching-related esophageal events in healthy volunteers during and after fast-food meals.

METHODS

Ten adult healthy volunteers had two lunches with a Big Mac® on different days, accompanied or not by Coca-Cola (500 mL, pH<3) in a random way. We assessed prandial and 2 h postprandial esophageal events using impedance-pH monitoring.

RESULTS

During meals with Coca-Cola, most signed belching (68 %) were concomitant with prolonged esophageal acidification or acid reflux, and the belching number was superior [median: 9.5 (IQR 4.7-14) vs. 0 (0-3); p=0.002] and less frequently represented by pure gas (24 % vs. 92 %; p<0.001) than in meals without Coca-Cola. Postprandial belching did not differ either in frequency [median: 15.5 (6-20.2) vs. 13.5 (10.7-20.5); p=0.739] or in type [(median %) pure gas: 6.7 % vs. 11.7 %; during acid reflux: 64.6 % vs. 51.7 %; during nonacid reflux: 22.5 % vs. 22.2 %; p=0.300), with more than 80 % of belching coincident with asymptomatic liquid reflux, regardless of Coca-Cola intake. Postprandial gastroesophageal reflux and esophageal acid exposure were similar, irrespective of Coca-Cola intake.

CONCLUSIONS

In healthy volunteers, a fast-food meal with Coca-Cola provoked a prompt reaction with increased prandial belching and esophageal acidification. Coca-Cola did not change postprandial belching, often accompanied by silent gastroesophageal liquid reflux.