Recovery of the small intestine in coeliac disease on a gluten‐free diet: Changes in intestinal permeability, small bowel morphology and T‐cell activity

Abstract Intestinal permeability was assessed before and 1, 2, 4, 8 and 12 weeks after commencing a gluten‐free diet (GFD) in eight coeliac subjects. Intestinal morphology was quantified in six coeliac subjects on a normal diet, six coeliac subjects on a GFD, and 21 normal subjects. T‐cell activity was measured in the eight coeliac subjects by soluble interleukin‐2 receptor (sIL‐2R) concentration (normal < 477 U/mL). Intestinal permeability was increased 10‐fold with a geometric mean value of 0.72 on a normal diet, and decreased to 0.17 at 4 weeks (P=0.04), to 0.07 at 8 weeks (P=0.010), and to 0.20 at 12 weeks (P=0.015) of a GFD. Two of the eight subjects showed a poor response to gluten withdrawal. Quantitative intestinal morphology showed no significant improvement after 3 to 6 months of a GFD. Mean ± s.d. sIL‐2R concentrations in the eight subjects were increased 5‐fold higher than control values at 1400 ± 530 U/mL on a normal diet and decreased to 750 ± 200 U/mL after 12 weeks of a GFD (P=0.004). We conclude that intestinal permeability improves rapidly in the majority of coeliac subjects after commencing a GFD, although some abnormal permeability and increased T‐cell activity persists. This may be due to varying degrees of gluten ingestion resulting in continued immune activation.