Effects of <i><scp>L</scp>actobacillus casei</i> supplementation on disease activity and inflammatory cytokines in rheumatoid arthritis patients: a randomized double‐blind clinical trial

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. Disease activity score-28 (DAS28) was calculated, European League Against Rheumatism (EULAR) response was evaluated and the cytokines, interleukin (IL)-1β, IL-6, IL-10, IL-12 and tumor necrosis factor (TNF)-α were measured. RESULTS: Thirty patients were recruited in each group; 22 and 24 patients were analyzed in the probiotic and placebo 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-α 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 alleviate symptoms and improve inflammatory cytokines.