Saccharomyces Boulardi can actually make some people incredibly ill, life threatening ill, if you have a strong immune system then you may be o.k. However, in some people S B can have and has had devastating results, so devastating that it can leave you fighting for your life.
There is always going to be someone who S B does not suit, there will be some it does make a huge difference and in some people it may not make any difference but you should check out all the information and see a doctor before embarking on it. If you have a person with autism do not give it without seeking professional advise first. If you have had a bad reaction to probiotics that have effected your immune system I would certainly see a doctor first, S B can be dangerous in some people with problems.
I am giving the worse case scenario as it has helped people on curezone. use your initiative.