RecruitingPhase 1Drug trialTreating Primary Sclerosing Cholangitis and Biliary Atresia With VancomycinThe purpose of this study is twofold. First, is to determine whether vancomycin is effective in the early treatment of Biliary Atresia (BA) and Primary Sclerosing Cholangitis (PSC), and if so, by what mechanism. Secondly, to characterize human intestinal microbial communities and their interactions with the host.