Improvement in intestinal permeability precedes morphometric recovery of the small intestine in coeliac disease

It is often difficult to assess small bowel recovery in adults with coeliac disease on a gluten-free diet (GFD). This prospective study compares chang es in intestinal permeability with changes in intestinal biopsy at various intervals after commencing a GFD. Intestinal permeability was measured by l actulose/rhamnose absorption from I week to 24 months after commencing a GF D. Intestinal morphometry was measured by villus area, crypt length and mit otic count per crypt at diagnosis and after commencing a GFD. Median intest inal permeability values decreased from 0.47 (n = 35) at diagnosis to 0.25 (n = 17) after I week and to 0.16 (n = 18) after 2 months of a GFD. Rhamnos e absorption improved significantly at an early stage, from 6.6% (untreated ) to 15.4% at 3 months of a GFD, whereas the decrease in lactulose permeati on took longer: from 3.4% (untreated) to 0.8% after 12 months of a G FD. Me an villus area (n = 29) was reduced to 16% of control values at diagnosis, and improved to a maximum of 48% after 6 months on a GFD, but did not chang e thereafter. Mean crypt length and mitotic count per crypt were increased by 222% and 356% respectively at diagnosis, and these parameters remained e levated at 172% and 216% above control values after 6 months of a GFD. We c onclude that intestinal permeability improves within 2 months after startin g a GFD, but that measurable intestinal biopsy improvement requires ingesti on of a GFD for at least 3-6 months, and even then remains incomplete.