Effects of a Fermented Milk Drink Containing Lactobacillus casei Strain Shirota on the Immune System in Healthy Human Subjects

Nine healthy volunteers drank fermented milk containing 4×10¹⁰ live cells of Lactobacillus casei strain Shirota daily for 3 weeks, and their NK activity and other immunological functions were measured. NK activity significantly increased (p<0.01) 3 weeks after the start of intake and remained elevated for the next 3 weeks. The effect was particularly prominent in low-NK-individuals.