Antioxidants have been a widely debated topic, especially for their importance in preventing and reducing the negative effects of free radicals which cause a number of serious, autoimmune diseases in recent years. I have also focused on the division of antioxidants, individual representatives and their main effects. The second part of bachelor thesis deals with the positive effects of probiotics on human health and their division. My thesis includes results of various studies which show whether the effects of antioxidants and probiotics are really beneficial for our health.