D J Morrison1, B Dodson, T Preston, L T Weaver. 1. Department of Child Health, University of Glasgow, Yorkhill Hospitals, Glasgow, G3 8SJ UK. dm94m@clinmed.gla.ac.uk
Abstract
OBJECTIVES: Lactose [(13)C]ureide has been proposed as a noninvasive marker for oro-caecal transit time in adults and children. The present study investigates the handling of lactose [(13)C]ureide ((13)C LU) and glucose [(13)C]ureide ((13)C GU) by the gastrointestinal tract and describes the metabolic fates of these substrates and describes the extent of tracer excretion by different routes. STUDY DESIGN AND SUBJECTS: Four subjects underwent five studies in which they ingested a test meal plus (1) no substrate, (2) (13)C LU, (3) (13)C GU, (4) (13)C LU after predosing with unlabelled lactose ureide and (5) (13)C LU after predosing with glucose ureide. Subjects were studied at home with at least 1 week between tests and they all completed the study. Breath was analysed for (13)CO(2) recovery and urine was analysed for total (13)C recovery, (13)C urea recovery and (13)C GU recovery. RESULTS: The profiles and extent of tracer recovery in breath and urine were similar when either (13)C GU or (13)C LU was used, suggesting similar handling of these substrates by the gut. (13)C GU was the major (13)C-enriched species recovered in the urine even when (13)C LU was consumed. Predosing with either lactose ureide or glucose ureide increased the rate of appearance of tracer, but did not alter transit times. CONCLUSIONS: (13)C LU is hydrolysed to (13)C GU in the small intestine with the fraction of (13)C GU appearing in the urine probably limited by small intestinal permeability. Either (13)C LU or (13)C GU can be used to measure oro-caecal transit time.
OBJECTIVES:Lactose[(13)C]ureide has been proposed as a noninvasive marker for oro-caecal transit time in adults and children. The present study investigates the handling of lactose[(13)C]ureide ((13)C LU) and glucose[(13)C]ureide ((13)C GU) by the gastrointestinal tract and describes the metabolic fates of these substrates and describes the extent of tracer excretion by different routes. STUDY DESIGN AND SUBJECTS: Four subjects underwent five studies in which they ingested a test meal plus (1) no substrate, (2) (13)C LU, (3) (13)C GU, (4) (13)C LU after predosing with unlabelled lactose ureide and (5) (13)C LU after predosing with glucose ureide. Subjects were studied at home with at least 1 week between tests and they all completed the study. Breath was analysed for (13)CO(2) recovery and urine was analysed for total (13)C recovery, (13)Curea recovery and (13)C GU recovery. RESULTS: The profiles and extent of tracer recovery in breath and urine were similar when either (13)C GU or (13)C LU was used, suggesting similar handling of these substrates by the gut. (13)C GU was the major (13)C-enriched species recovered in the urine even when (13)C LU was consumed. Predosing with either lactose ureide or glucose ureide increased the rate of appearance of tracer, but did not alter transit times. CONCLUSIONS: (13)C LU is hydrolysed to (13)C GU in the small intestine with the fraction of (13)C GU appearing in the urine probably limited by small intestinal permeability. Either (13)C LU or (13)C GU can be used to measure oro-caecal transit time.
Authors: Nicole Reichardt; Andrew R Barclay; Lawrence T Weaver; Douglas J Morrison Journal: Appl Environ Microbiol Date: 2011-09-23 Impact factor: 4.792
Authors: Robert J Schillinger; Simutanyi Mwakamui; Chola Mulenga; Mizinga Tembo; Phoebe Hodges; Ellen Besa; Kanta Chandwe; Victor O Owino; Christine A Edwards; Paul Kelly; Douglas J Morrison Journal: Front Med (Lausanne) Date: 2022-07-29
Authors: Jutta Keller; Heinz F Hammer; Paul R Afolabi; Marc Benninga; Osvaldo Borrelli; Enrique Dominguez-Munoz; Dan Dumitrascu; Oliver Goetze; Stephan L Haas; Bruno Hauser; Daniel Pohl; Silvia Salvatore; Marc Sonyi; Nikhil Thapar; Kristin Verbeke; Mark R Fox Journal: United European Gastroenterol J Date: 2021-06-14 Impact factor: 4.623