We investigated 10 lactic acid bacteria strains with probiotic potential prepared from Mongolian dairy products for their ability to induce T helper type-1 (Th1) cytokine production in mouse immune cells in vitro and in vivo. Among these strains, the Lactobacillus plantarum 06CC2 strain was effective in elevating the level of interleukin (IL)-12p40 in co-culture with J774.1 cells and the levels of IL-12 and interferon (IFN)-γ in co-culture with mouse spleen cells in vitro. Oral administration of this strain augmented the gene expression of IFN-γ and IL-12p40 and enlarged the population of CD4(+), CD25(+), and CD49b(+) cells in the spleens of normal mice. It also significantly elevated the gene expression of IL-12 receptor β2 as well as IL-12p40 and IFN-γ in Peyer's patches. Thus oral administration of strain 06CC2 was effective in inducing Th1 cytokine production activating the Th1 immune response associated with intestinal immunity in normal mice.