Quantitative microbiome profiling disentangles inflammation- and bile duct obstruction-associated microbiota alterations across IBD/PSC diagnoses

Disease-association microbiome dataset comprising 106 primary sclerosing cholangitis and/or inflammatory bowel disease (PSC/IBD) patients. Assessing quantitative taxon abundances, we study microbiome alterations beyond symptomatic stool moisture variation. We observe a high prevalence of a low cell count Bacteroides2 enterotype across patient groups when compared to healthy controls, with microbial loads correlating inversely with intestinal and systemic inflammation markers. Quantitative analyses allow us to differentiate between taxa associated to either intestinal inflammation severity (Fusobacterium) or cholangitis/biliary obstruction (Enterococcus) among previously suggested PSC marker genera. We identify and validate a near-exclusion pattern between the inflammation-associated Fusobacterium and Veillonella genera, with Fusobacterium detection being restricted to Crohn’s disease (CD) and PSC-CD patients. Overall, through absolute quantification and confounder control, we single out clear-cut microbiome markers associated to pathophysiological manifestations and disease diagnosis.EGA study EGAS00001003600