Retraction:The Effects of Probiotic Supplementation on Gene Expression Related to Inflammation

Background: Limited data are available assessing the effects of probiotic supplementation on gene expression related to inflammation, insulin, and lipids in patients with multiple sclerosis (MS). Objectives: The current study was conducted to assess the effects of probiotic supplementation on gene expression related to inflammation, insulin, and lipids in patients with MS. Methods: This randomized, double-blind, placebo-controlled clinical trial was performed among 40 patients with MS. Participants were randomly assigned into two groups to receive either a probiotic capsule containing Lactobacillus acidophilus, Lactobacillus casei, Bifidobacterium bifidum, and Lactobacillus fermentum (2 × 109 colony-forming units/g each; n = 20) or placebo (n = 20) for 12 weeks. Gene expression related to inflammation, insulin, and lipids was quantified in blood samples of patients with MS with the reverse transcription polymerase chain reaction (RT-PCR) method. Results: 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. Conclusions: Overall, probiotic supplementation for 12 weeks in patients with MS significantly improved gene expression of IL-8 and TNF-α but did not influence IL-1, PPAR-γ, or LDLR.