A new study uses single-cell transcriptomics from a 12-week clinical trial to reveal how kimchi influences the immune system.
With seasonal shifts increasing the circulation of respiratory infections such as colds and influenza, a new clinical study has provided scientific evidence that kimchi, a traditional Korean fermented food, can boost the activity of human immune cells and help maintain overall immune balance.
The World Institute of Kimchi, a government-funded research institute under the Ministry of Science and ICT, announced that its single-cell genetic analysis revealed immunomodulatory effects linked to kimchi intake. According to the findings, kimchi can help curb excessive immune reactions while at the same time strengthening the body’s defensive responses. This is the first study to clarify kimchi’s immunological effects at the single-cell level and to demonstrate that its benefits extend beyond metabolic health to include immune health as well.
The study enrolled overweight adults who were separated into three groups (n = 13 each). Each group consumed either a placebo, kimchi powder produced through natural fermentation, or kimchi powder made using a starter culture for a period of 12 weeks. After the intervention, researchers collected peripheral blood mononuclear cells (PBMCs) and performed single-cell transcriptomics analysis (scRNA-seq). By monitoring gene expression shifts in individual cells with this advanced method, the team uncovered subtle immune changes that traditional testing approaches would likely miss.
How kimchi alters immune cell behavior
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.
Expert perspective and broader implications
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.
Reference: “Single-cell RNA sequencing reveals that kimchi dietary intervention modulates human antigen-presenting and CD4⁺ T cells” by Wooje Lee, Ha-Rin Moon, Hasun Choi, Ho Jae Lee, Yebin Kim, Hyun Ju Kim, Ye-Rang Yun, Min-Sung Kwon and Sung Wook Hong, 17 November 2025, npj Science of Food.
DOI: 10.1038/s41538-025-00593-7
Funding: Ministry of Science and ICT
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2 Comments
Fermented foods are how you can get Vitamin K2. Use it along with your vitamin D supplement. They are somewhat synergistic.
{^_^}
Are all fermented foods the same? It stands to reason that the ingredients are as important as the fermenting bacteria. But this study does not seem to differentiate between types of kimchi, which seems an oversight.
Of greatest interest is that there is a World Institute of Kimchi. I wonder if there is a Sauerkraut Institute or Pickle U.