Characterisation of the faecal microbiota in Japanese patients with paediatric-onset primary sclerosing cholangitis

Dear Sir, Primary sclerosing cholangitis (PSC) is a liver disease often associated with IBD.1 Dysbiosis of the gut microbiota is implicated in PSC aetiology in adults,2–4 but less is known about paediatric-onset PSC. We analysed the faecal microbiota of 27 Japanese patients with paediatric-onset PSC as well as 16 age-matched patients with UC and 23 healthy controls (HCs) (see online supplementary table S1) with pyrosequencing data of 16S rRNA gene V1-V2 region (accession #DRA004773). We assessed the influence of medications on the gut microbiota and found that salazosulfapyridine (SASP) treatment affected the microbiota structure with significant changes in the abundance of six major genera between the treated and untreated patients with PSC, perhaps due to its bactericidal property (see online supplementary figure S1). We thus report the analysis of 13 patients with PSC and 15 patients with UC and 23 HCs, all SASP untreated (see online supplementary table S2). ### Supplementary tables [gutjnl-2016-312533supp_tables.pdf] ### Supplementary figure [gutjnl-2016-312533supp_figure.pdf] Clustering analysis of the 16S reads revealed that the microbiota in the PSC and HC groups had significantly high species richness compared with the UC group, and the species richness of PSC samples was lower than that of HCs. The PSC group also exhibited an intermediate trend in the Shannon's index between the UC and HC groups (figure 1A). The unweighted UniFrac metric revealed a significant difference in the overall microbiota structure among the three groups, in which the PSC samples tended to aggregate between the HC and UC samples (figure 1B, C). Collectively, the data suggested that the patients with …