Abdominal distension after eating lettuce: The role of intestinal gas evaluated in vitro and by abdominal CT imaging

Abstract

Background: Some patients complain that eating lettuce, gives them gas and abdominal distention. Our aim was to determine to what extent the patients' assertion is sustained by evidence. Methods: An in vitro study measured the amount of gas produced during the process of fermentation by a preparation of human colonic microbiota (n = 3) of predigested lettuce, as compared to beans, a high gas-releasing substrate, to meat, a low gas-releasing substrate, and to a nutrient-free negative control. A clinical study in patients complaining of abdominal distention after eating lettuce (n = 12) measured the amount of intestinal gas and the morphometric configuration of the abdominal cavity in abdominal CT scans during an episode of lettuce-induced distension as compared to basal conditions. Key Results: Gas production by microbiota fermentation of lettuce in vitro was similar to that of meat (P =.44), lower than that of beans (by 78 ± 15%; P