Thanks for the post Agnes, but I just have to wonder if this is something like rhubarb or for that matter any plant or chemical activity that happens naturally. It may be of a benefit to our bodies prepared a certain way, but just a slight change of chemical compounds and it becomes hazardous. It seems like nutrional yeast has had some wonderful effects for some people. I do however believe that some individuals are sensitive and allergic to certain compounds and should avoid it for their health, but I do not believe that it should be banned just because of one person suffering from an allergic reaction. Again that would be like getting on the band wagon against comfrey or st.john's wort. Someone gets sick because of not taking the herbal medicine in 'good common sense' or reading what different herbalists have to say, and suffers the consequences of misuse. I can only encourage not only myself but anyone who has concerns to read and study more about something that is not 'quite right'. So please keep us posted as to what new has been discovered, I'm sure we would all really appreciate the information.