Regression of lactose malabsorption in coeliac patients after receiving a gluten-free diet.

OBJECTIVE: In a recent study by our group, it was shown that a large proportion of patients with lactose malabsorption and with no bacterial overgrowth are affected by silent coeliac disease (CD). Our aim was to evaluate the effect of a gluten-free diet on lactose malabsorption assessed using the hydrogen lactose breath test (LBT) and also the relationship with normalization of duodenal biopsies in coeliac patients. MATERIAL AND METHODS: Fifteen patients (11 F, 4 M; mean age 35.8+/-6) affected by CD with a positive LBT and negative glucose breath test were enrolled. All were started on a gluten-free diet and were re-evaluated after 6 months by LBT and after 12 months by both LBT and upper gastrointestinal endoscopy with biopsies. RESULTS: LBT normalization was observed in 1 out of 15 patients (6.7%) after 6 months and in 9 of the remaining 14 (64.2%) after 12 months. Duodenal biopsies showed normal villi in 8 patients, partial villous atrophy in 5 and total atrophy in 2. CONCLUSIONS: The present study shows that a large proportion of CD patients experience a regression of lactose malabsorption after receiving a gluten-free diet. This may be related to normalization of the brush border with an improvement of lactase enzyme activity. LBT should be performed after 12 months in CD patients on a gluten-free diet in order to assess the persistence/disappearance of lactose malabsorption, thus avoiding an unnecessary lactose-free diet.