Antioxidant Potential of Probiotics and Postbiotics: A Biotechnological Approach to Improving Their Stability

Today there is an increasing amount of scientific evidence of the effects of probiotic bacteria as components of the gut microbiota on human health. Among their numerous health benefits are their antioxidant (AO) properties attracting more and more attention. Lactobacilli and bifidobacteria are the most important part of the human gut microbiome. Many in vivo and in vitro studies have demonstrated that they and their cellular components exhibit AO properties, thereby providing a certain degree of protection to the human body and contributing to the prevention of oxidative-stress-related diseases. The review discusses the AO properties of probiotic bacteria and postbiotics that are still not well known to the public. Special emphasis was put on the mechanisms of AO activity of lactobacilli and bifidobacteria, in which are involve enzymes, cell components and different metabolites as potential postbiotics. The genes encoding proteins, involved in AO activity, identified in various strains of lactobacilli and bifidobacteria were considered. The review also discusses different biotechnological methods that improve the survival rate of probiotics during processing, storage and GIT transit like microbial encapsulation that was successfully employed by many authors. Probiotic bacteria and postbiotics can be considered today as a new source of natural AO and can be used for biotechnological applications, specifically for pharmaceuticals, nutraceuticals, and cosmetic products.