Rice bran, guar, xantum, and konjac will do absolutely nothing effective against systemic candidiasis.
In a small way you are right. It is not the fibers that do the work. The fibers are fermented by the flora to generate the acids that control the Candida.
By the way, Candida RARELY ever goes systemic.
Liver flushing and eating a highly alkalizing diet will do absolutely everything.