Imbalances in faecal and duodenal Bifidobacterium species composition in active and non-active coeliac disease

Abstract

Background: Gut bifidobacteria are believed to influence immune-related diseases. The objective of this study was to assess the possible relationships between the gut bifidobacteria composition and coeliac disease (CD) in children. A total of 48 faecal samples (30 and 18 samples from active and no active CD patients, respectively) and 33 duodenal biopsy specimens of CD patients (25 and 8 samples from active and non-active CD patients, respectively) were analysed. Samples (30 faecal samples and 8 biopsies) from a control age-matched group of children were also included for comparative purposes. Gut Bifidobacterium genus and species were analyzed by real-time PCR.

Results: Active and non-active CD patients showed lower numbers of total Bifidobacterium and B. longum species in faeces and duodenal biopsies than controls, and these differences were particularly remarkable between active CD patients and controls. B. catenulatum prevalence was higher in biopsies of controls than in those of active and non-active CD patients, whereas B. dentium prevalence was higher in faeces of non-active CD patients than in controls. Correlations between levels of Bifidobacterium and B. longum species in faecal and biopsy samples were detected in both CD patients and controls.

Conclusion: Reductions in total Bifidobacterium and B. longum populations were associated with both active and non-active CD when compared to controls. These bacterial groups could constitute novel targets for adjuvant dietary therapies although the confirmation of this hypothesis would require further investigations.

Figure 1

Correlations of bifidobacterial groups of faecal and duodenal biopsy samples from all children (active and non-active CD patients and controls) under study. Data represent the positive samples. The line in the box is the median (50% percentile), with the lower line the lower 25% border (25% percentile) and the upper line the 75% (75% percentile) border. The end of the upper vertical line is the maximum data value, outliers not considered. The end of the lower vertical line is the lowest value, outliers not considered. The separate dots or asterisks indicate outliers. Significant differences (P < 0.050) were found between faeces and biopsy levels of every bifidobacterial group analysed when considering all subjects.