<qa>  What is the name of the antibiotic vancomycin used for?Firstly, to see if the antibiotic vancomycin may be used for the early treatment of Biliary Atresia BA and Primary Sclerosing Cholangitis PSC. The investigators hope to learn what effect Vancomycin has on the bacteria that are present in stool, body fluid or intestinal tissue on someone who has BA and PSC and if so by what mechanism. Secondly, the investigators hope to learn to characterize human intestinal microbial communities microbiome: the collection or collectivity of microorganisms using molecular methods, examine the mechanisms of interaction between host and microbiome using genomic approaches, and determine how the microbiome both preserves local health and promotes pathology. The investigators will focus on primary sclerosing cholangitis, biliary atresia, as well as states of health. The composition of the associated microbiome will be assessed based on ribosomal DNA and RNA sequences, and attention will be given to richness diversity, evenness relative abundance, and variation with respect to time, person, and anatomic niche. Host response at the adjacent mucosal surface will be assessed based on genome-wide gene expression patterns. 