https://search.dev.ndltd.org/etd/massey/oai:mro.massey.ac.nz:10179/7393
type: CreativeWork
name: The aspirin augmented standardized lactulose mannitol test as a measure of the 'health' of the gastrointestinal tract : a thesis presented in partial fulfilment of the requirements for the degree of Doctor of Philosophy at Massey University, Palmerston North, New Zealand
description: In this thesis, I studied the ‘classical’ lactulose mannitol test for intestinal permeability that has been used to measure the integrity of the intestinal mucosa and thus to provide an index of recovery from inflammatory bowel disease (IBD) and from autoimmune diseases such as coeliac disease. Perusal of the literature indicates that the protocol for the test has not been standardized and a variety of different test protocols have been used. Hence there are differences in the duration of urinary sampling, the doses of the two test probes, the volumes of fluid consumed during the test and the administration of the test during the fasted or fed state. There is therefore a need for a standardized test. The bulk of the research conducted in this thesis was to develop an optimal protocol with a standardized osmolarity (720 osmol l-1) for the test solution that contained 10 g of lactulose and 5 g of mannitol dissolved in 100 ml of water. Similarly the total fluid intake was standardized to 700 ml. The volumes of fluid consumed over the experimental period were also standardized in order to control for any osmolar effects of the test drink and to hydrate the subjects sufficiently to enable them to produce half-hourly urine samples of a reasonable volume. The rates of excretion and the timings of the peaks in the excretion of mannitol and lactulose were found to vary over time in healthy subjects. Hence the rate of mannitol excretion peaked during the first two hrs whilst the rate of lactulose excretion peaked at four hrs. The correlation between urinary excretion with intestinal transit times were confirmed using a wireless motility capsule. The work with the wireless motility capsule indicated that the probe sugars were in the small intestine from 2½ - 4 hrs and in the proximal colon from 4½ - 6 hrs following dosage with the test solution. Hence a sample collected during the 2½ - 4 hr period is best for assessing permeability of the small intestinal mucosa in healthy sub…
abstract: In this thesis, I studied the ‘classical’ lactulose mannitol test for intestinal permeability that has been used to measure the integrity of the intestinal mucosa and thus to provide an index of recovery from inflammatory bowel disease (IBD) and from autoimmune diseases such as coeliac disease. Perusal of the literature indicates that the protocol for the test has not been standardized and a variety of different test protocols have been used. Hence there are differences in the duration of urinary sampling, the doses of the two test probes, the volumes of fluid consumed during the test and the administration of the test during the fasted or fed state. There is therefore a need for a standardized test. The bulk of the research conducted in this thesis was to develop an optimal protocol with a standardized osmolarity (720 osmol l-1) for the test solution that contained 10 g of lactulose and 5 g of mannitol dissolved in 100 ml of water. Similarly the total fluid intake was standardized to 700 ml. The volumes of fluid consumed over the experimental period were also standardized in order to control for any osmolar effects of the test drink and to hydrate the subjects sufficiently to enable them to produce half-hourly urine samples of a reasonable volume. The rates of excretion and the timings of the peaks in the excretion of mannitol and lactulose were found to vary over time in healthy subjects. Hence the rate of mannitol excretion peaked during the first two hrs whilst the rate of lactulose excretion peaked at four hrs. The correlation between urinary excretion with intestinal transit times were confirmed using a wireless motility capsule. The work with the wireless motility capsule indicated that the probe sugars were in the small intestine from 2½ - 4 hrs and in the proximal colon from 4½ - 6 hrs following dosage with the test solution. Hence a sample collected during the 2½ - 4 hr period is best for assessing permeability of the small intestinal mucosa in healthy sub…
author: Sequeira, Ivana Roosevelt
keywords: Gastrointestinal mucosa, Analysis, Mannitol, Lactulase, Aspirin, Research Subject Categories::MEDICINE::Physiology and pharmacology
date published: 2015
date modified: 2026-07-27T20:18:16Z
provider: Massey University
publisher: Networked Digital Library of Theses and Dissertations
type: WebPage
source organization: Massey University