You need to read this paper. It will explain some of your questions about brand issues. Also understand that there are 6 sources for the API (active pharmaceutical ingredient). We do not know exactly what has the efficacy for PSC – certainly if we had funding we could do a study. I actually have the former MD, PhD CEO of a pharma company interested in doing this study. Buness2020_Article_SuccessfulResponseOfPrimaryScl.pdf (1.3 MB)
here is a link that combines the 3 YouTube links you posted: Vancomycin for Primary Sclerosing Cholangitis (PSC) Roundtable: Featuring Dr. Cox and Dr. El-Youssef - YouTube