Effects of oral administration of probiotics from Mongolian dairy products on the Th1 immune response in mice.

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.