IAG supplies arabinogalactans, derived from the Larch tree. Arabinogalactans are long, densely branched, high-molecular weight polysaccharides, which act as a natural activators of the immune system's complement pathway. The complement pathway is responsible for non-specific host defense mechanisms. Studies have also documented Arabinogalactanís ability to enhance the cytotoxicity of Natural Killer Cells. In addition to immune support, IAG is also considered a prebiotic, as it is able to support the growth of friendly bacteria.