Immunoenhancing and antioxidant potentials of kimchi, an ethnic food from Korea, as a probiotic and postbiotic food

Abstract

Kimchi, the traditional lactic fermented vegetables from Korea, is globally praised for its potential as a functional food owing to the presence of beneficial microorganisms known as probiotics. However, the serving of kimchi in traditional Korean dishes often involves cooking at high temperature, thus killing the probiotics. Recently, non-viable or inactivated microorganisms and their metabolites, known as postbiotics, were shown to confer health benefits when consumed, thus giving rise to a novel potential of kimchi as a postbiotic food with health functionalities. The present study aimed to explore the potential of uncooked and cooked kimchi, both as a probiotic and postbiotic food, respectively, using an animal model. Mice were fed by AIN-76 diet enriched in 10% freeze-dried uncooked or cooked kimchi for 28 days prior to kill. Several parameters related to immune system and antioxidant were evaluated. Exposure of kimchi toward heat in steaming process killed the microorganisms in kimchi, but did not alter its antioxidant activity. Interestingly, the consumption of uncooked and cooked kimchi stimulated the growth of lactic acid bacteria in the intestine indifferently, as shown in the fecal matter. In addition, kimchi supplementation, either uncooked or cooked, increased the number of splenic lymphocytes and intestinal IgA, supporting the role of kimchi in the immune system. Furthermore, kimchi supplementation reduced the level of lipid peroxidation in the fecal matter, indicating its antioxidant activity in vivo. Taken together, the findings in this study suggest the potential of kimchi both as a probiotic and postbiotic food with antioxidant and immunoenhancing properties.