Duodenal-Mucosal Bacteria Associated with Celiac Disease in Children
ABSTRACTCeliac disease (CD) is an immune-mediated enteropathy triggered by the ingestion of cereal gluten proteins. This disorder is associated with imbalances in the gut microbiota composition that could be involved in the pathogenesis of CD. The aim of this study was to characterize the composition and diversity of the cultivable duodenal mucosa-associated bacteria of CD patients and control children. Duodenal biopsy specimens from patients with active disease on a gluten-containing diet (n= 32), patients with nonactive disease after adherence to a gluten-free diet (n= 17), and controls (n= 8) were homogenized and plated on plate count agar, Wilkins-Chalgren agar, brain heart agar, or yeast, Casitone, and fatty acid agar. The isolates were identified by partial 16S rRNA gene sequencing. Renyi diversity profiles showed the highest diversity values for active CD patients, followed by nonactive CD patients and control individuals. Members of the phylumProteobacteriawere more abundant in patients with active CD than in the other child groups, while those of the phylumFirmicuteswere less abundant. Members of the familiesEnterobacteriaceaeandStaphylococcaceae, particularly the speciesKlebsiella oxytoca,Staphylococcus epidermidis, andStaphylococcus pasteuri, were more abundant in patients with active disease than in controls. In contrast, members of the familyStreptococcaceaewere less abundant in patients with active CD than in controls. Furthermore, isolates of theStreptococcus anginosusandStreptococcus mutansgroups were more abundant in controls than in both CD patient groups, regardless of inflammatory status. The findings indicated that the disease is associated with the overgrowth of possible pathobionts that exclude symbionts or commensals that are characteristic of the healthy small intestinal microbiota.