From the Manufacturer:
Symbiotics Colostrum Plus features key natural Immune Factors such as Immunoglobulins, which are types of proteins that are used by the immune system to identify and neutralize foreign objects, as well as Lactoferrin, which is a multifunctional protein and Proline-Rich Polypeptides, which have a very powerful effect in actively modulating the immune response.*
The Immune Factors found in Symbiotics Colostrum Plus have a dual action effect, working in the bloodstream, as well as in the GI tract, by maintain healthy intestinal flora in a normal GI tract.* Under the Symbiotics label, minimum levels of these important Immune Factors are veri fied by laboratory testing."