Influence of the Protein Content of a Meal on Postprandial pH and PCO₂ in the Human Duodenum

Abstract

Rune, S. J. Influence of the protein content of a meal on postprandial pH and PCO₂ in the human duodenum. Scand. J. Gastroent. 1973, 8, 605-608.

The pH and PCO₂ were measured in small samples of duodenal contents, aspirated from the second part of the duodenum each 15 min for 4 hours after a meal. Each of 10 subjects was given a liquid test meal on two subsequent days. The protein content was 7 cal% on one day and 25 cal% on the other day, in randomized order. During the second and the third post-prandial hour the duodenal pH was found to be around 0.7 units lower after the high-protein meal than after the low-protein meal (p < 0.01), while no significant difference was found in the first and the fourth hour. The PCO₂ was very high after both meals, around 500 mm Hg, being slightly higher after the high-protein meal than after the low-protein meal during the third and the fourth hour (p < 0.05). It is concluded that the influence of the protein content of a meal on duodenal pH must be due to the different titratable acidity of the gastric contents more than to the difference in pH of these contents.

Key-words::

• Diets
• duodenal PCO₂
• duodenal pH
• gastric secretion