I don't have time to watch the videos. I just read the descriptions of them. Some I can agree with. Antibiotic can kill off your normal bacteria and leave surfaces open to the growth of Candida or some really bad actor bacteria (like multi-antibiotic resistant Staphylococcus). So yes it is wise to avoid taking antibiotics for trivial reasons (like the common cold). You also could get yeast overgrowth.
However one person who gets better does not prove that Candida causes MS. If I had MS, and the Candida control method was not dangerous, I might try it, what the heck.....
Also Boroch is not saying that Candida is THE cause of cancer.