Abstract
Objectives Gut microbiota gets altered in patients with celiac disease (CeD) and whether these microbiota changes are the cause or effect of the disease is not well understood to date. The first degree relatives (FDRs) of CeD patients are genetically susceptible and may represent a pre-diseased state. Therefore, understanding differences in duodenal and faecal microbiota composition between the FDR and CeD subjects is of interest. To investigate this, we characterised the microbiota in duodenal biopsies and faeces of CeD patients (n = 23), FDRs (n = 15) and control subjects (DC, n= 24) by 16S rRNA gene sequencing.
Results Duodenal biopsies showed more diverse pattern in microbial community composition and structure than faecal samples. In duodenal biopsies, 52 OTUs and 41 OTUs were differentially abundant between the FDR and DC group, and between the FDR and CeD group respectively (p < 0.01). In faecal samples, 30 OTUs were differentially abundant between FDR and DC, and 81 between FDR and CeD (p < 0.01). Predicted metagenomes from duodenal microbiomes of FDR and CeD showed a lower genetic potential for metabolizing gluten as compared to controls.
Conclusions The microbial communities of FDR and CeD groups are more similar to each other than to the control groups. Significant differences at OTU level suggest that specific bacterial taxa may be important for pathogenesis of CeD. Moreover, the predicted differences in gluten metabolism potential by the FDR and CeD microbiota point towards the need for investigating functional capabilities of specific bacterial taxa in healthy FDR and CeD patients.
List of abbreviations
- CeD
- Celiac disease
- DC
- Diseased controls (dyspeptic)
- FDR
- First degree relatives
- OTU
- Operational taxonomic unit
- PERMANOVA
- Permutational multivariate analysis of variance
- rRNA
- Ribosomal Ribonucleic acid
- PCoA
- Principal coordinates analysis
- CCA
- Canonical correspondence analysis