Gluten-Free Diet Normalizes Mouth-to-Cecum Transit of a Caloric Meal in Adult Patients with Celiac Disease

The mechanisms responsible for boweldisturbances in celiac disease are still relativelyunknown. Recent reports suggested that small bowel motorabnormalities may be involved in this pathologicalcondition; however, there are no studies addressing smallbowel transit in celiac disease before and after agluten-free diet. We studied the mouth-to-cecum transittime of a caloric liquid meal in a homogeneous group of celiac patients presenting with clinical andbiochemical evidence of malabsorption and complaining ofdiarrhea. Sixteen patients were recruited andinvestigated by means of hydrogen breath test through ingestion of 20 g lactulose together with anenteral gluten-free diet formula. A urinary D-xylosetest was also done in each patient. Both breath testsand D-xylose tests were carried out basally and after a period of gluten-free diet. Twenty healthyvolunteers were recruited as a control group andunderwent the same breath testing. At the time of thediagnosis, mouth-to-cecum transit time was significantly prolonged in celiacs with respect to controls(243 ± 10 vs 117 ± 6 min, P = 0.0001). TheD-xylose test was also abnormal (average urinaryconcentration 2.8 ± 0.25 g, normal values>4.5). No correlation was found in patients between mouth-to-cecum transit timeand urinary D-xylose output (r = 0.22). After thegluten-free diet period, mouth-tocecum transit time inceliacs was significantly reduced compared to prediet transit (134 ± 8 vs 243 ± 10 min,P = 0.0001) and did not show statistical difference whencompared to that found in controls (P = 0.1). TheD-xylose test reverted to normal in all but twosubjects, who were found to be noncompliant with the diet.Mouth-to-cecum transit time is significantly prolongedin patients affected by untreated celiac disease whencompared to healthy controls. This alteration might notbe correlated to intestinal malabsorption, and theprolonged orocecal transit could be due to impairedsmall bowel function (deranged motility?). Sinceintestinal transit returned to normal values after an adequate gluten-free period, a link with severeactive mucosal lesions is suggestive.