To determine deficiencies in intestinal permeability, the lactulose/rhamnose (L/R) intestinal permeability test is widely used.
Deficiencies in intestinal permeability
To determine deficiencies in intestinal permeability, the lactulose/rhamnose (L/R) intestinal permeability test is widely used. This barrier function test is based on the comparison of intestinal permeation of a larger molecule with that of a smaller molecule by measuring the ratio of these molecules in the blood serum. The two molecules follow different routes of intestinal permeation: the larger molecules are assumed to permeate para cellular, and the smaller molecules are assumed to permeate transcellular.
Knowledge of the intestinal barrier function has implications for the aetiology and the pathogenesis of various intestinal and systemic disorders, such as coeliac disease, inflammatory bowel disease, immuno-deficiency syndromes, ankylosing spondylitis, cystic fibrosis, iron deficiency, atopic eczema, and many other disorders.
Quantifying mannitol, rhamnose, lactose and lactulose
Quantifying mannitol, rhamnose, lactose and lactulose in a matrix containing high levels of common blood sugars such as glucose, galactose and sucrose is key to the intestinal permeability test. The separation, achieved with a Metrosep Carb 2 – 250/4.0, utilized a sodium hydroxide/Sodium acetate mobile phase. Quantification of the sugars was carried out by applying pulsed amperometric detection (PAD) over a gold electrode.