ABSTRACT
152Oxidative stress is a physiological condition characterized by a disrupted balance between oxidants such as reactive oxygen and nitrogen species (ROS/ RNS) and antioxidants (e.g., glutathione, peroxidase, catalase) in favor of the former. Such condition has been associated to different human pathologies (e.g., cancer, neurogenerative, and cardiovascular diseases) by causing damage to basic component for cell function and survival. Therefore, several strategies have been explored in order to regulate the redox homeostasis including the use of phytochemicals (polyphenols, carotenoids), vitamins (E and C), minerals (Zn), and proteins (bioactive peptides). Recent in vitro and in vivo studies have shown that ingestion of food-grade lactic acid bacteria (LAB) may reinforce antioxidant defense systems of the host, thereby alleviate oxidative stress related-pathologies. Nevertheless, the protective mechanisms of LAB are not fully elucidated. It has been suggested that the possible effect may be due to (1) bacteria ROSand RNS-scavenging properties, (2) chelating metal ions (iron and copper) involved in ROS/RNS formation, and (3) bacteria capacity to produce antioxidant compounds such as bioactive peptides, polysaccharides, and fatty acids. Therefore, the aim of this chapter is to provide an overview of potential protective role of foodgrade lactic acid bacteria against oxidative stress as well as to describe the possible mechanism involved.
