The “gut microbiota” hypothesis in primary sclerosing cholangitis

Primary sclerosing cholangitis (PSC) is a rare, immune-related disease characterized by chronic biliary inflammation and fibrosis of the intra and/or extra-hepatic biliary tree, leading to end-stage liver disease and biliary cancer. No medical therapies have demonstrated impact on the overall survival and liver transplantation (LT) is the only curative therapy (1). PSC is a complex condition characterized by the interplay between genetic predisposition and still unknown environmental factors. A better understanding of the disease etiopathogenesis would allow the development of specific therapies. The gut microbiota has recently evolved as a new important player in the pathophysiology of many intestinal and extraintestinal diseases, such as inflammatory bowel diseases (IBD), diabetes, obesity. It is to note that trials in PSC engaged antibiotics, both metronidazole and vancomycin, have shown a reduction in the alkaline phosphatase (ALP) (2,3). These data might suggest that manipulation of the gut microbiota could potentially influence the disease process in PSC.