**1. Introduction**

*Oxidative stress* is a process that leads to an increase in the level of oxygen radicals within the cell, which in turn causes damage to vital macromolecules (such as lipids, proteins, and nucleic acids) in the body [1]. Reactive oxygen species (ROS) are reactive molecules that contain superoxide anion radicals, hydroxyl radicals, and hydrogen peroxide. By contrast, natural antioxidants contain enzymatic antioxidants, such as superoxide dismutase (SOD), glutathione reductase (GR), and glutathione peroxidase (GPx), as well as non-enzymatic antioxidants, such as various types of vitamins, glutathione, and carotenoids, which have been formed during the evolution of organisms to prevent damage caused by oxidative stress [2]. Synthetic antioxidant additives can be used to prevent the oxidation of cellular compounds and thus prevent damage due to oxidative stress. The use of synthetic antioxidants has been questioned due to some reported side effects. Therefore, the preparation and use of natural antioxidants instead of synthetic antioxidants have attracted much attention [3, 4]. Probiotics are non-pathogenic microorganisms so sufficient consumption of them is beneficial for gastrointestinal health [4]. They also show antioxidant properties in various ways [5–8].
