P0804OPBG Metagenome

Cystic fibrosis (CF), is a lethal hereditary disorder leading to respiratory infections, chronic inflammation, repeated antibiotic treatments, all of them have a known or suspected link to the gut microbiota. The aim of this work was to investigate the gut microbiota composition and modulation of CF patients by metagenomic and metabolomic combined analyses in relation with healthy children. Thirty faecal samples from either CF patients and healthy children (HC) (age range 1-6 years), were collected. After the filtering protocols, a total of 316,006 sequence reads of 16S rRNA gene amplicons were obtained with an average of 5,356 reads/sample and an average length of 487 bp calculated after primer removal. The results of alpha-diversity analysis indicated a satisfactory coverage of the microbial diversity as shown by the Good’s estimated sample coverage (ESC) that was in all cases above 97%. The sample type (CF vs HC) significantly influenced the composition of the microbiota as measured using ADONIS and ANOSIM methods (p<0.001). Accordingly, beta-diversity analyses performed by unweighted uniFrac showed a clear differentiation between CF and HC individuals suggesting that different taxa characterized the fecal microbiota of the two types of subjects. In fact, Clostridiaceae were more abundant in CF (avg. 20%) compared to HC (avg. 3%) samples (p<0.005) while Ruminococcaceae and Erysipelotrichaceae were more abundant in HC samples (p<0.005). At deeper taxonomic assignment, Clostridium sp. (avg. 9.8% in CF vs 2.2 in HC) and Clostridium difficile (avg. 2.9% in CF vs 0.0 in HC) were more abundant in CF patients (p=0.04 and p=0.01, respectively). By contrast, Eggerthella sp., Eggerthella lenta, Ruminococcus sp., Ruminococcus bromii, Dialister sp. and Dialister invisus were more abundant in HC feces (p<0.05).