Overview
In collaboration with Meguro Medical Clinic, Nihon Kefia Co., Ltd. conducted a human clinical trial to evaluate the immune-activating properties of its original kefir (NKG Kefir), with a particular focus on its impact on salivary secretory immunoglobulin A (S-IgA) levels.

What is S-IgA?
Secretory IgA is a crucial antibody found in mucosal secretions such as saliva, tears, and intestinal fluids. It acts as the first line of immune defense on mucosal surfaces, playing a vital role in:

• -Preventing adhesion and colonization of viruses and bacteria,
• -Neutralizing allergens like pollen,
• -Supporting oral and respiratory health.

Study Design

• -Participants: . A total of 19 people including 10 people with cedar pollinosis and 9 healthy people
• -Method: Participants consumed NKG kefir daily for 12 weeks
• -Measurement: Saliva samples were collected and analyzed to measure changes in S-IgA levels before and after intake.

Key Findings
The trial showed a statistically significant increase in salivary S-IgA after consumption of NKG kefir. This result suggests that the kefir has an immunostimulatory effect on mucosal immunity, enhancing the body’s natural ability to defend itself against pathogens at mucosal entry points like the mouth and nose.

Why It Matters

• -Strengthens daily immune defense, particularly important during cold, flu, and allergy seasons.
• -Supports oral and upper respiratory health, making it especially relevant for people exposed to environmental pathogens or allergens.
• -Science-backed evidence for the role of fermented foods in activating mucosal immunity.

Conclusion
This clinical trial further reinforces the functional food value of NKG kefir. By increasing levels of S-IgA, Nihon Kefia’s product contributes to the body’s natural immune defenses, offering a scientifically supported way to maintain wellness through daily dietary habits.