The possibility of using beta-1,3/1,6-glucan in human medicine has been met with skepticism, possibly because some results of clinical investigations have not been reproducible. This is, however, most probably due to discrepancies in dosage and application methods and also because of poorly characterized and defined chemistry of the glucan preparations used. It is not enough to refer to a substance as beta-1,3-glucan. One must understand the molecular structure to be able predict any effect. For example, it is a presupposition for macrophage activating ability and biological effect of a beta-1,3/1,6-glucan that the molecule has branches in 6 positions on the beta-1,3-glucan chain. In addition, the effect of the beta-1,3/1,6-glucan varies with the frequency and length of these side branches (see 4.1).
Another cause for skepticism can be that scientists/researchers, being used to the ideas from specific immunology, simply have not believed in immunetherapy with substances that are targeted on innate immune mechanisms. A change has occurred in recent years, however, as this “Ancient system gets new respect” (Gura 2001).