A distinctive 'microbial signature' in celiac pediatric patients

Background: Celiac Disease (CD) is an autoimmune disorder of the small intestine in which dietary gluten ingestion leads to a chronic enteropathy. Recently, scientific evidence suggested a potential role of gut microbiota in CD. To have a snapshot of dominant duodenal microbiota we analyzed the mucosa-associated microbiota of 20 children with CD, before and after a gluten-free diet (GFD) regimen, and of 10 controls. Total DNA was extracted from duodenal biopsies and amplification products of 16S ribosomal DNA were compared by temporal temperature gradient gel electrophoresis (TTGE). TTGE profiles were analyzed by statistical multivariate analysis. Results: The average number of bands in TTGE profiles was significantly higher (P < 0.0001) in active (n.b. 16.7 +/- 0.7) and inactive states (n.b. 13.2 +/- 0.8) than in controls (n.b. 3.7 +/- 1.3). Mean interindividual similarity index was 54.9% +/- 14.9% for active disease, 55.6% +/- 15.7% for remission state and 21.8% +/- 30.16% for controls. Similarity index between celiac children before and after GFD treatment was 63.9% +/- 15.8%. Differences in microbiota biodiversity were among active and remission state (P = 0.000224) and amid active CD and controls (P < 0.001). Bacteroides vulgatus and Escherichia coli were detected more often in CD patients than in controls (P < 0.0001). Conclusions: Overall, the results highlighted a peculiar microbial TTGE profile and a significant higher biodiversity in CD pediatric patients' duodenal mucosa. The possible pathophysiological role of these microbial differences needs further characterization.