Mechanism Unveiled for How 'Lactobacillus Lacticaseibacillus paracasei KW3110,' Confirmed to Alleviate Mild to Moderate Hay Fever Symptoms, Induces IL-12 Production in Human Dendritic Cells for Immune Regulation
Kirin HD has elucidated the mechanism by which 'Lactobacillus KW3110,' discovered by the company, acts on human immune cells to promote the production of 'IL-12,' which suppresses allergic reactions like hay fever. This research strengthens the scientific basis for immune care through food.
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- 📰 Published: April 8, 2026 at 20:00
- 🔍 Collected: April 8, 2026 at 11:31
- 🤖 AI Analyzed: April 20, 2026 at 15:35 (292h 3m after Collected)
The Health Science Research Institute (Director: Koichiro Murashima) of Kirin Holdings Company, Limited (President and COO: Takeshi Minakata, hereinafter 'Kirin') has clarified how the lactic acid bacterium *Lacticaseibacillus paracasei* KW3110 (hereinafter, 'L. paracasei KW3110')*1 acts on human dendritic cells.
This study revealed the molecular mechanism by which *L. paracasei* KW3110 is taken up by dendritic cells*2, a type of human immune cell, and the lactic acid bacterium-derived RNA*3 is recognized within the cells. This induces the production of the cytokine*5 'Interleukin-12 (hereinafter, IL-12)'*6, which suppresses type 2 inflammation*4, the cause of allergic reactions like hay fever. This provides new scientific insights into how *L. paracasei* KW3110 is involved in the immune response in human dendritic cells.
The results of this research have been accepted for publication as a scientific paper in the 'International Archives of Allergy and Immunology'*7.
*1 International Archives of Allergy and Immunology. 2004;135:205–215
*2 A type of immune cell that engulfs foreign substances that have entered the body and is involved in activating the immune response.
*3 A molecule involved in the transmission of genetic information within cells.
*4 A type of allergic inflammation.
*5 A type of signaling molecule involved in allergic reactions.
*6 A type of cytokine that suppresses allergic reactions caused by type 2 inflammation.
*7 International Archives of Allergy and Immunology | Karger Publishers
According to the 'Hay Fever Survey 2026' conducted by Weathernews Inc., more than one in two people reported having hay fever*8. In recent years, symptoms such as sneezing, runny nose, and nasal congestion due to hay fever (seasonal allergic symptoms) have significantly disrupted daily life. The impact on quality of life (QOL) is particularly severe*9, and hay fever is beginning to be recognized as a societal issue. Allergic reactions like hay fever are said to be deeply related to immune cells such as Th2 cells, which cause type 2 inflammation. Since these cells cause an excessive inflammatory response to substances like pollen, dust mites, and house dust, leading to allergic symptoms, it is important to prevent the aggravation of type 2 inflammation. Kirin has previously conducted experiments comparing the amount of cytokines that suppress type 2 inflammation (e.g., IL-12) released by *L. paracasei* KW3110 and lactic acid bacteria from commercial yogurts. The results showed that *L. paracasei* KW3110 has a higher ability to produce these cytokines compared to other lactic acid bacteria (Figure 1), and clinical trials have confirmed that it alleviates mild to moderate hay fever symptoms*10.
This study revealed the molecular mechanism by which *L. paracasei* KW3110 is taken up by dendritic cells*2, a type of human immune cell, and the lactic acid bacterium-derived RNA*3 is recognized within the cells. This induces the production of the cytokine*5 'Interleukin-12 (hereinafter, IL-12)'*6, which suppresses type 2 inflammation*4, the cause of allergic reactions like hay fever. This provides new scientific insights into how *L. paracasei* KW3110 is involved in the immune response in human dendritic cells.
The results of this research have been accepted for publication as a scientific paper in the 'International Archives of Allergy and Immunology'*7.
*1 International Archives of Allergy and Immunology. 2004;135:205–215
*2 A type of immune cell that engulfs foreign substances that have entered the body and is involved in activating the immune response.
*3 A molecule involved in the transmission of genetic information within cells.
*4 A type of allergic inflammation.
*5 A type of signaling molecule involved in allergic reactions.
*6 A type of cytokine that suppresses allergic reactions caused by type 2 inflammation.
*7 International Archives of Allergy and Immunology | Karger Publishers
According to the 'Hay Fever Survey 2026' conducted by Weathernews Inc., more than one in two people reported having hay fever*8. In recent years, symptoms such as sneezing, runny nose, and nasal congestion due to hay fever (seasonal allergic symptoms) have significantly disrupted daily life. The impact on quality of life (QOL) is particularly severe*9, and hay fever is beginning to be recognized as a societal issue. Allergic reactions like hay fever are said to be deeply related to immune cells such as Th2 cells, which cause type 2 inflammation. Since these cells cause an excessive inflammatory response to substances like pollen, dust mites, and house dust, leading to allergic symptoms, it is important to prevent the aggravation of type 2 inflammation. Kirin has previously conducted experiments comparing the amount of cytokines that suppress type 2 inflammation (e.g., IL-12) released by *L. paracasei* KW3110 and lactic acid bacteria from commercial yogurts. The results showed that *L. paracasei* KW3110 has a higher ability to produce these cytokines compared to other lactic acid bacteria (Figure 1), and clinical trials have confirmed that it alleviates mild to moderate hay fever symptoms*10.