Someone asked me if I can explain the refined yeast powder part in candida probiotics' ingredients. I have used the Threelac which contains it and it works okay, but I couldn't get a real response from the company when asked for supporting information about the Japanese product, sales figures, etc. They would not provide any answers except for sales. All they would tell me is that the Japanese firm was private and didn't have to comply with the request.
From personal experience, it helps prevent big flare ups if I eat something bad or have some wine. If the yeast is nutritional, it doesn't feed the Candida. Nutritional yeast differs from baking yeast and, in many cases, from Brewer's Yeast because it is very high in B vitamins, especially B12, but does not contain live yeast or any candida yeast components. Some, like Red Mill certify that theirs is free from any candida.
I did research the individual ingredients against candida and found some solid information, so I bought it and tried it. As for the yeast, I said flavor because I get no response from the company, but I knew that some nutritional yeasts were okay to use with the condition.
I haven't found it to be a cure, a treatment perhaps. The only way that I have found people to write about being cured were using "zappers", another with 200 billion plus probiotics daily for an extreme amount of time with the diet, and Karen Tripp (SF722, diet, supplements). Those are the only extensive ones that I can find with cures.