Intestinal Permeability

Rationale: Intestinal permeability of subjects can vary depending on their health status. It is therefore important to be able to measure and quantify intestinal permeability in a standardized way. Subjects with intestinal complaints (like irritable bowel disorder) or obese subjects have been found to have increased intestinal permeability. Different physiological conditions might affect intestinal permeability (IP) further. In the clinic, sugar absorption tests and different blood and urine markers have been used to quantify IP. The sugars sucrose, mannitol, sucralose and lactulose are absorbed differently in the small or large intestines, resulting in different sugar levels in urine. This indicates the level of intestinal permeability and the location of increased permeability which is more or less permeable. A high-fat meal could be used as a challenge test to increase IP in subjects even further. After a high fat meal, lipopolysaccharide (LPS) could be co-transported with chylomicrons. Small amounts of LPS co-transit with dietary fat from the gut after a high-fat meal, which thereby increases plasma LPS concentrations. Because of the above mentioned reasons, it could be relevant to determine intestinal permeability and plasma LPS concentration after consumption of a high-fat diet. Different methods will be used to determine the intestinal permeability in lean and obese men, under different conditions. New parameters, like intestinal (I) fatty acid binding protein (I-FABP), liver (L)-FABP, LPS and inflammatory markers will be measured and related to outcomes of tests, to examine the relation with intestinal permeability. The association of IP with whole body electrical resistance will be examined, to determine usefulness of a candidate non-invasive method for IP investigation.