Geography of intestinal permeability and absorption

I S Menzies,^*b M J Zuckerman,^c W S Nukajam,^b S G Somasundaram,^a B Murphy,^a A P Jenkins,^b R S Crane,^a G G Gregory^d

^a Department of Clinical Biochemistry, King's College School of Medicine and Dentistry, Bessemer Road, London SE5 9PJ, UK, ^b St Thomas's Hospital, Lambeth Palace Road, London SE1 7EH, UK, ^c Department of Medicine, Texas Tech University Health Sciences Centre, 4800 Alberta Avenue, El Paso, Texas 79905, USA, ^d Department of Mathematical Sciences, University of Texas at El Paso, El Paso, Texas 79968, USA

Correspondence to: Dr Zuckerman.

Accepted for publication 15 October 1998

BACKGROUNDIntestinal morphology and function vary geographically.
AIMSThese functions were assessed in asymptomatic volunteers in European, North American, Middle Eastern, Asian, African, and Caribbean countries.
METHODSFive hour urine collections were obtained from each subject following ingestion of a 100 ml iso-osmolar test solution containing 3-0-methyl-D-glucose, D-xylose, L-rhamnose, and lactulose after an overnight fast, to assess active (3-0-methyl-D-glucose) and passive (D-xylose) carrier mediated, and non-mediated (L-rhamnose) absorption capacity, as well as intestinal permeability (lactulose:rhamnose ratio).
RESULTSA comparison of results for subjects from tropical countries (n=218) with those resident in the combined temperate and subtropical region (Europe, United States, Qatar) (n=224) showed significant differences. Residents in tropical areas had a higher mean lactulose:rhamnose ratio and lower mean five hour recoveries of 3-0-methyl-D-glucose, D-xylose, and L-rhamnose, indicating higher intestinal permeability and lower absorptive capacity. Investigation of visiting residents suggested that differences in intestinal permeability and absorptive capacity were related to the area of residence. Subjects from Texas and Qatar, although comprised of several ethnic groups and resident in a subtropical area, showed no significant difference from European subjects.
CONCLUSIONSThere are clearly demarcated variations in intestinal permeability and absorptive capacity affecting asymptomatic residents of different geographical areas which correspond with the condition described as tropical enteropathy. Results suggest the importance of environmental factors. The parameters investigated may be relevant to the predisposition of the indigenous population and travellers to diarrhoeal illness and malnutrition. Intestinal function in patients from the tropics may be difficult to interpret, but should take into account the range of values found in the asymptomatic normal population.
(Gut 1999;44:483-489)

Keywords: intestinal permeability;  absorption;  tropical enteropathy;  non-invasive sugar absorption/permeability test