We found that compared with placebo, probiotic supplementation down-regulated gene expression of interleukin-8 (IL-8; p < 0.001) and tumor necrosis factor-alpha (TNF-α) mRNA (p < .001) in peripheral blood mononuclear cells of patients with MS. We did not observe any significant effect of probiotic supplementation on gene expression of interleukin-1 (IL-1), peroxisome proliferator-activated receptor gamma (PPAR-γ), or oxidized low-density lipoprotein receptor (LDLR) in peripheral blood mononuclear cells of patients with MS.