The effect of green kiwifruit on gas transit and tolerance in healthy humans

Abstract

Background: Green kiwifruit is a fiber-rich fruit that has been shown effective for treatment of constipation. However, fermentation of fibers by colonic bacteria may worsen commonly associated gas-related abdominal symptoms. Aim: To determine the effect of green kiwifruit on transit and tolerance to intestinal gas in humans. Methods: In 11 healthy individuals, two gas challenge tests were performed (a) after 2 weeks on a low-flatulogenic diet and daily intake of 2 green kiwifruits and (b) after 2 weeks on a similar diet without intake of kiwifruits. The gas challenge test consisted in continuous infusion of a mixture of gases into the jejunum at 12 mL/min for 2 hours while measuring rectal gas evacuation, abdominal symptoms, and abdominal distension. During the 2 weeks prior to each gas challenge test (on-kiwifruit and off-kiwifruit), the number and consistency of stools, and abdominal symptoms were registered. Key Results: Intake of kiwifruits was associated with more bowel movements per day (1.8 ± 0.1 vs 1.5 ± 0.1 off-kiwifruit; P =.001) and somewhat looser stools (Bristol score 3.3 ± 0.2 vs 2.8 ± 0.1 off-kiwifruit; P =.072) without relevant abdominal symptoms. Gas infusion produced similar gas evacuation (1238 ± 254 mL and 1172 ± 290 mL; P =.4355), perception of symptoms (score 1.2 ± 0.2 and 1.3 ± 0.3; P =.2367), and abdominal distension (17 ± 7 mm and 17 ± 6 mm; P =.4704) while on-kiwifruit or off-kiwifruit. Conclusions and Inferences: In healthy subjects, green kiwifruit increases stool frequency without relevant effects on intestinal gas transit and tolerance. If confirmed in patients, these fruits may provide a natural and well-tolerated treatment alternative for constipation.