The goal of this paper was to study the effect of Lactobacillus reuteri B1/1, B2/1 and B6/1 on the relative expression of selected interleukins (IL-1β, IL-15), macrophage inflammatory protein (MIP-1β), and the relative percentage of T lymphocyte subpopulations in peripheral mononuclear blood cells (PMBCs). The mRNA expression levels of interleukins and MIP-1β of PMBCs were evaluated at 24 h and 48 h post inoculation using the quantitative real-time polymerase chain reaction (qRT-PCR). The percentage of T lymphocyte subpopulations in PMBCs was determined by flow cytometry. The group that was administered L. reuteri B1/1 had the most significant stimulation of the expression of pro-inflammatory interleukins and MIP-1β, in particular after 24 h. Similarly, we observed a rise in the relative percentage of T cells including CD3+, CD4+ and CD8+ lymphocytes in the groups with L. reuteri B1/1 and L. reuteri B2/1. Overall, L. reuteri B1/1 and L. reuteri B2/1 showed a promising stimulatory effect on the relative expression of pro-inflammatory interleukins, MIP-1β and percentage of T cell subpopulations in vitro. On the flip side, L. reuteri B6/1 did not induce the expression of the IL-1β gene.
