The effect of gluten on intestinal fermentation, gastric and gallbladder emptying in healthy volunteers

Background: The relationship between gluten ingestion and gastrointestinal tract function is a matter of debate. Aim: We analysed the effect of gluten on gastric and gallbladder emptying and intestinal fermentation in healthy volunteers. Methods: Ultrasound measurement of gastric and gallbladder emptying after both gluten-containing and gluten-free meals was performed in 18 volunteers (8 women, age 25.0 +/- 2.5 years; BMI 22 +/- 1.9). Breath hydrogen excretion after a gluten-containing meal, a gluten-free meal and a gluten-free meal with added gluten powder was measured in 16 volunteers (10 women, age 25.2 +/- 2.7 years; BMI 22 +/- 1.8). The severity of symptoms was monitored. Results: Gluten presence in the meals was not recognised. Gastric emptying time was 81.6 +/- 13.8 min after gluten-containing and 73.9 +/- 21.6 min after gluten-free meals (p = 0.11). Percentage ejection fraction after gluten-containing meals was 60 +/- 9% and 60.6 +/- 6% after gluten-free meals (p = 0.68). Peak and cumulative hydrogen excretion were significantly higher after gluten-containing than after gluten-free meals (peak: 12.5 +/- 7.3 vs 6.5 +/- 5.1 parts-per-million, p < 0.01; and cumulative: 2319 +/- 1720 vs 989 +/- 680 parts-per-million/minute, respectively; p < 0.01). Adding gluten powder to the gluten-free meal did not modify fermentation. Symptoms were mild and not different after the meals. Conclusions: In healthy volunteers, gluten may induce gastrointestinal alterations. Further studies are needed to clarify which patients could benefit from dietary modification. (C) 2015 Editrice Gastroenterologica Italiana S.r.l. Published by Elsevier Ltd. All rights reserved.