Kimchi consumption strengthens antigen recognition and immune regulation

Amid concerns about the simultaneous spread of multiple respiratory diseases, such as colds and influenza, with the change of seasons in current times, a recent clinical study has scientifically proven that kimchi, a traditional Korean fermented food, enhances the function of human immune cells and maintains the balance of the immune system.

The World Institute of Kimchi (President: Hae Choon Chang), a government-funded research institute under the Ministry of Science and ICT, has reported the results of a single-cell genetic analysis that suggests that kimchi consumption has immunomodulatory effects, which include the suppression of excessive immune responses while simultaneously enhancing defense functions. This is the first study in the world that has elucidated the immunological effects of kimchi at the single-cell level and has shown that kimchi consumption can contribute not only to metabolic health but also to immunological health.

The participants in this study were overweight adults, divided into three groups (n = 13 each). Participants in each group consumed either a placebo, kimchi powder made from naturally fermented kimchi, or kimchi powder made from kimchi fermented with a starter culture for 12 weeks. After the 12-week intervention, peripheral blood mononuclear cells (PBMCs) were collected, and single-cell transcriptomics analysis (scRNA-seq) was conducted. By tracking the changes in the gene expression of each cell using this cutting-edge technique, the research team was able to reveal subtle changes in immune responses that are difficult to detect using conventional tests.

The analysis of the results indicated that in the kimchi-consuming groups, the function of antigen-presenting cells (APCs), which recognize external invaders, such as bacteria and viruses, and transmit signals, was strengthened. Also, the CD4+ T cells differentiated into defense cells and regulatory cells in a balanced manner. These results suggest that kimchi does not just stimulate the immune system, but also acts as a 'precision regulator' that enhances the defense capabilities of the immune system if necessary and suppresses unnecessary and excessive responses.

In addition, differences were observed in the immunomodulatory effects according to the kimchi fermentation method used. While both naturally fermented and starter-fermented kimchi had positive effects in maintaining immune balance, the latter showed a more pronounced immunomodulatory effect in terms of strengthening the antigen-recognition ability of immune cells and suppressing unnecessary signals. These results suggest that the health functionality of kimchi can be systematically enhanced using starter technology in the future.

Dr. Woo Jae Lee of the World Institute of Kimchi, who led the research team, said, "Our research has proven for the first time in the world that kimchi has two different simultaneous effects: activating defense cells and suppressing excessive response." He also emphatically added, "We plan to expand international research on kimchi and lactic acid bacteria in relation to immune and metabolic health in the future."

The results of this research contribute to establishing kimchi as not just a traditional fermented food but also as a functional food with scientifically proven effects on immune health. The findings of this study are expected to be utilized in various fields, including the development of health functional foods, the improvement of vaccine efficacy, and the prevention of immune diseases. The results of the research were published in npj Science of Food (IF 7.8), a highly ranked international academic journal in the field of food science.