Gastric emptying of liquid meals measured noninvasively in humans with [13C]acetate breath test.

The aim of the present study was to develop a breath test to measure liquid gastric emptying rates that would be without radiation exposure and applicable to field testing. Four different test meals were investigated: a glucose meal, an amino acid meal, a fat meal, and a mixed meal (Ensure). The test meals were labeled with two markers, [13C]acetate and PEG-4000 (polyethylene glycol 4000). Gastric emptying rates were measured simultaneously by both breath test and the double-indicator technique in eight healthy male subjects. The appearance of 13CO2 in the breath closely reflected gastric emptying of the four test meals as measured by the double-indicator technique. It is concluded that the [13C]acetate breath test is a reliable, noninvasive test to measure gastric emptying rates of liquid test meals.