Characterization of the blood microbiota in children with Celiac disease

Highlights • Bacteroidetes is most abundant phylum in pediatric blood. • Beta diversity is increased in blood of children with active Celiac. • Abundance of taxa are altered in blood of children with active Celiac.
Celiac Disease (CD) is an autoimmune disorder triggered by gluten ingestion that can develop in genetically predisposed individuals. Alterations in the gut microbiota have been suggested to contribute to development of autoimmune conditions including CD. Recent work suggests the existence of a blood microbiota. Evidence that alterations in the blood microbiota potentially influence the development of chronic immune based diseases is increasing. However, there is no published literature regarding the blood microbiota in children, including those with CD. This study aimed to characterize the diversity and taxonomic composition of the blood microbiota of children with CD compared to controls. Whole blood samples were collected from children with active CD, CD in remission, and control subjects and 16S rRNA sequencing was utilized to analyze the blood microbiota. We found 16s rRNA present throughout all pediatric blood samples, providing evidence for the presence of a pediatric blood microbiota. We found significant differences in beta diversity and in abundance of certain taxa (Campylobacterales order, Odoribacteraceae and Helicobacteraceae families, Odoribacter genus and species, and Bacteroides acidifaciens species) between subjects with active CD and controls. These taxa have been previously reported to be associated with immune response and gut-inflammatory diseases. We did not find significant differences between subjects with active and remission CD or between remission CD and controls. Conclusions: We provide evidence for a pediatric blood microbiota and identified higher beta diversity and alterations in the composition of blood microbiota in subjects with active CD compared to controls.