Gastric relaxation in response to a soup meal in healthy subjects. A study using a barostat in the proximal stomach.

BACKGROUND

Meal-induced relaxation of the proximal stomach can be investigated by means of a barostat. Using a standard liquid meat soup that elicits symptoms and a wide antrum in patients with functional dyspepsia, we aimed at finding the best meal size and fat load for studying gastric relaxation.

METHODS

In the first trial 200 ml and 500 ml meat soup (1 g fat/200 ml) was given to six healthy individuals. In the second trial a constant volume of soup (200 ml) containing graded amounts of fat (1, 10, and 20 g/200 ml) was given to seven healthy individuals. Gastric relaxation was investigated for 1 h after consumption of the soup. A sagittal cross-sectional antral was assessed ultrasonographically every 10 min, and abdominal discomfort was scored.

RESULTS

Overall, a positive response (volume increase of 30 ml or more within 5 min after consumption of the meal) was found in 26 of 30 (87%) investigations. Individual maximal responses ranged from 38 to 482 ml (mean, 180 ml +/- 128). Area under the time-volume curve (AUC) was similar after 200 and 500 ml soup (mean, 100 ml/30 min and 107 ml/30 min, respectively). AUC increased with increasing fat content, with a significant difference between the low-fat and high-fat meal (p < 0.05). The barostat bag induced fed-state antral contractions in most individuals (p < 0.001). There was a negative correlation between AUC and postprandial abdominal discomfort (p = 0.04).

CONCLUSIONS

The barostat is a sensitive technique for detecting gastric relaxation, also in response to our standard meat soup meal. The postprandial relaxation response in healthy individuals in dependent on the fat content of the meal. The barostat bag may alter gastric motor activity. Abdominal discomfort after soup ingestion may be related to poor gastric relaxation.