Macerates of diverse fruits and vegetables sequentially fermented by various strains of Lactobacilli, so-called “Regulates”, are in use as health promoting food additives in traditional medicine. They contain a wealth of polyphenolic compounds well known for their antioxidant activities. With the aid of biochemical model reactions simulating pathological processes such as inflammations (activated PMNs, peroxynitrite), induction of atherosclerosis (LDL oxidation) and ischemia-reperfusion (xanthine oxidase, Fenton chemistry) we demonstrate that Regulates 1) exhibit excellent antioxidant properties compared to the critical standard gallic acid, and 2) preactivate human polymorphonuclear leukocytes in whole blood at low concentrations, reversing this effect at higher ones. From our data we conclude that consumption of Regulates may actively support immune reactions of the leukocytes by two mechanisms: pre-stimulation of the innate immune response in the sense of probiotic tuning and the attenuation of oxidative stress which accompanies such processes.