New research re-affirms the beneficial role that fermented dairy plays in human immunity. Researchers supplemented health individuals with a fermented-milk beverage (presumably Kefir) daily for 3 weeks. During that time levels of Natural Killer cells (a powerful part of the immune system and good indicator of overall immune system health) were monitored. During the study Natural Killer cell activity increased significantly—and it stayed increased for 3 weeks after they stopped using the drink!
Fermented dairy products have long played a role in natural health—this adds to the scientific evidence for that role. Yogurt and/or kefir should be a part of your regular diet.
Read the study.