Systematic review: microbial manipulation as therapy for primary sclerosing cholangitis

BACKGROUND: Primary sclerosing cholangitis (PSC) is a progressive liver disease with poor prognosis and no effective therapies to prevent progression. An aetiopathological link between PSC and gastrointestinal microbial dysbiosis has been suggested. AIM: To evaluate all potential medical therapies which may exert their effect in PSC by modulation of the gut‐liver axis. METHODS: We conducted a comprehensive scoping review of PubMed and Cochrane Library, including all articles evaluating an intervention aimed at manipulating the gastrointestinal microbiome in PSC. RESULTS: A wide range of therapies proposed altering the gastrointestinal microbiome for the treatment of PSC. In particular, these considered antibiotics including vancomycin, metronidazole, rifaximin, minocycline and azithromycin. However, few therapies have been investigated in randomised, placebo‐controlled trials. Vancomycin has been the most widely studied antibiotic, with improvement in alkaline phosphatase reported in two randomised controlled trials, but with no data on disease progression. Unlike antibiotics, strategies such as faecal microbiota transplantation and dietary therapy can improve microbial diversity. However, since these have only been tested in small numbers of patients, robust efficacy data are currently lacking. CONCLUSIONS: The gut‐liver axis is increasingly considered a potential target for the treatment of PSC. However, no therapies have been demonstrated to improve transplant‐free survival. Innovative and well‐designed clinical trials of microbiome‐targeted therapies with long‐term follow‐up are required for this orphan disease.