Not sure about biotin, but I do know that my candida symptoms improved a good deal approximately one year ago when I took biotin daily for a short time to try to reverse hair loss. Mind you, I had no idea at that time that it was actually the candida that was causing my hair loss, or that I even had candidiasis at all.
So maybe there is something to biotin after all. I still have some laying around, so I will post if I see any improvements from it.