Human gut microbiota Metagenome

Inflammatory bowel disease (IBD), including Crohn disease and ulcerative colitis (UC), causes a profound disruption of gut homeostasis. Given that secretory IgA (SIgA) may shape the composition of the human gut microbiota, we elucidated the relative impact of SIgA1 and SIgA2 binding to intestinal microbes by profiling fecal bacteria from 6 healthy controls (HC) through a combination of IgA1 - and IgA2-based bacterial sorting and 16S ribosomal RNA (16S rRNA) sequencing. 16S rRNA amplicons from each of these bacterial fractions were generated and sequenced as previously described (Magri et al, Immunity 2017). In parallel we compared the composition of fecal bacteria from HCs (n=14) and UC patients (n=14) by combining SIgA1-based bacteria sorting with 16S rRNA gene sequencing. In both experiments, to identify and exclude possible bacterial contaminants, sheath fluid samples collected in between sample sorting procedures were also sequenced and analyzed.