Impact of Cystic Fibrosis Disease on Archaea and Bacteria Composition of Gut Microbiota

Cystic fibrosis is often associated with intestinal inflammation due to several factors, including altered gut microbiota composition. In this study, we analyzed the fecal microbiota among cystic fibrosis patients of 10-22 years of age, and compared the findings with age-matched healthy subjects. The participating patients included fourteen homozygotes and fourteen heterozygotes with the delF508 mutation, and two heterozygotes presenting non-delF508 mutations. We used PCR-DGGE and qPCR to analyze the presence of bacteria, archaea, and sulfate-reducing bacteria. Overall, our findings confirmed disruption of the cystic fibrosis gut microbiota. Principal component analysis of the qPCR data revealed no differences between homozygotes and heterozygotes, while both groups were distinct from healthy subjects who showed higher biodiversity. Archaea were under the detection limit in all homozygotes subjects, whereas methanogens were detected in 62% of both cystic fibrosis heterozygotes and healthy subjects. Our qPCR results revealed a low frequency of sulfate-reducing bacteria in the homozygote (13%) and heterozygote (13%) cystic fibrosis patients compared with healthy subjects (87.5%). This is a pioneer study showing that cystic fibrosis patients exhibit significant reduction of H2-consuming microorganisms, which could increase hydrogen accumulation in the colon and the expulsion of this gas through non-microbial routes.