ORIGINAL ARTICLE Effects of Lactobacillus casei supplementation on disease activity and inflammatory cytokines in rheumatoid arthritis patients: a randomized double-blind clinical trial Beitullah ALIPOUR, 1 Aziz HOMAYOUNI-RAD, 2 Elnaz VAGHEF-MEHRABANY, 3 Sakineh Khatoun SHARIF, 4 Leila VAGHEF-MEHRABANY, 5 Mohammad ASGHARI-JAFARABADI, 6 Mohammad Reza NAKHJAVANI, 4 and Javad MOHTADI-NIA 2 1 Department of Community Nutrition, Tabriz University of Medical Sciences, Tabriz, 2 Department of Food Science and Technology, Tabriz University of Medical Sciences, Tabriz, 3 Department of Nutrition, Biochemistry and Diet Therapy, Faculty of Nutrition,Tabriz University of Medical Sciences, Tabriz, 4 Department of Rheumatology, Faculty of Medicine, Tabriz University of Medical Sciences, 5 Department of Nutrition, Faculty of Nutrition and Diet Therapy, Tehran University of Medical Sciences, Tehran, and 6 Traffic Injury Prevention Research Center, Faculty of Health, Tabriz University of Medical Sciences, Tabriz, Iran Abstract Aim: The present study aimed at investigating the effects of Lactobacillus casei 01 supplementation on symptoms and inflammatory biomarkers of rheumatoid arthritis (RA) in women. Method: In this randomized double-blind clinical trial, female patients with established RA for more than 1 year, 20–80 years of age and body mass index (BMI) lower than 40, who followed stable medication for 3 months prior to the supplementation, were randomly allocated to receive either one capsule containing 10 8 colony forming units (CFU) of L. casei 01, or a placebo for 8 weeks; allocation was stratified by BMI and menopausal status. Dis- ease activity score-28 (DAS28) was calculated, European League Against Rheumatism (EULAR) response was evalu- ated and the cytokines, interleukin (IL)-1b, IL-6, IL-10, IL-12 and tumor necrosis factor (TNF)-a were measured. Results: Thirty patients were recruited in each group; 22 and 24 patients were analyzed in the probiotic and pla- cebo groups, respectively. L. casei 01 supplementation decreased serum high-sensitivity C-reactive protein (hs-CRP) levels, tender and swollen joint counts, global health (GH) score and DAS28 (P < 0.05). More patients in the L. casei 01 group had moderate response to the treatment, based on the EULAR criteria, at the end of the study (P < 0.01). At the end of the study, a significant difference was observed between the two groups for IL- 10, IL-12 and TNF-a changes through the study course (P < 0.05), in favor of the probiotic group. No adverse effects were reported for the intervention. Conclusion: Probiotic supplementation may be an appropriate adjunct therapy for RA patients and help allevi- ate symptoms and improve inflammatory cytokines. Key words: DAS28, EULAR criteria, inflammatory cytokines, probiotics, rheumatoid arthritis. INTRODUCTION Rheumatoid arthritis (RA) is an inflammatory debilitat- ing autoimmune disease with an unknown etiology which affects 0.5–1.0% of adults worldwide. 1,2 Evi- dence from human studies have revealed that RA patients have altered gut microbiota. 3–6 In an adjuvant- Correspondence: Elnaz Vaghef-Mehrabany, Faculty of Nutrition, Tabriz University of Medical Sciences, Attar Neyshabouri Ave., Golgasht St., P.O. Box 14711, Tabriz 5166614711, Iran. Email: vaghefe@tbzmed.ac.ir; elnaz.vaghef@gmail.com and Javad Mohtadi-Nia, Tabriz University of Medical Sciences, Attar Neyshabouri Ave., Golgasht St., Tabriz, Iran. Email: mohtadiniaj@tbzmed.ac.ir © 2014 Asia Pacific League of Associations for Rheumatology and Wiley Publishing Asia Pty Ltd International Journal of Rheumatic Diseases 2014; 17: 519–527