Effect of synbiotic supplementation on disease activity, Th17 cells frequency,IL-23/IL-17 axis expression and serum levels of IL-17 and IL-23 in patients with ankylosing spondylitis

Abstract

T‐helper 17 (Th17) cells and interleukin (IL)-17/IL-23 pathway have a substantial activity in pathogenesis of ankylosing spondylitis (AS). Synbiotics, a combination of prebiotics and probiotics, are nutritional supplements that improve immunomodulative abilities and have been reported to be helpful in managing autoimmune inflammatory disorders. This randomized double-blind, placebo-controlled trial was designed to assess the effects of synbiotic supplement on IL-17/IL-23 pathway and disease activity in AS patients. Forty-eight AS patients were randomly allocated to use one synbiotic capsule or placebo daily for 12 weeks. Disease activity, Th17 cells proportion, gene expression, and serum levels of cytokines including IL-17 and IL-23 were assessed before and after trial. Thirty-eight patients (19 in each group) finished the study. Synbiotic supplementation significantly reduced proportion of Th17 cells (4.88±2.47 vs. 2.16±1.25, P<0.001), gene expression of IL-17 (1.03±0.24 vs. 0.65±0.26, P<0.001) and IL-23 (1.01±0.13 vs. 0.68±0.24, P<0.001), and serum IL-17 (38.22±14.40 vs. 24.38±11.68, P=0.002) and IL-23 (51.77±17.40 vs. 32.16±12.46, P<0.001) compared with baseline. Substantial between-group differences were only noticed in proportion of Th17 cells, and gene expression of IL-17 and IL-23 (P<0.001, P=0.002, and P=0.006, respectively), adjusting for baseline measures and disease duration. Furthermore, synbiotic supplementation did not significantly change Bath Ankylosing Spondylitis Disease Activity Index (BASDAI) and Bath Ankylosing Spondylitis Disease Functional Index (BASFI) score compared with baseline and placebo group (P>0.05). Overall, present research indicated benefits of synbiotic supplement in decreasing inflammation in AS patients without any effect on disease activity. Additional studies are warranted to acknowledge these preliminary results.