Work

Efficacy and safety of probiotic supplementation in PsA—a randomized controlled trial

Year: 2026

Type: article

Study designs: Randomized Controlled Trial, Clinical Trial

Abstract: OBJECTIVES: To evaluate the clinical efficacy and safety of a multispecies probiotic in patients with PsA in moderate disease activity. METHODS: In this single-centre, randomized, double-blind, placebo-controlled trial (RCT), 66 PsA patients with moderate disease activity (Psoriatic Arthritis Disease Activity Score [PASDAS] > 3.2 to <5.4) on stable immunomodulatory therapy were randomized 1:1 to receive either a multispecies (Lactobacillus, Bifidobacterium) probiotic or placebo for 12 weeks. The primary outcome was treatment response at week 12, defined as achieving low disease activity or remission (PASDAS ≤3.2) without treatment change. Secondary outcomes included gut permeability markers, immune cell and microbiome composition. Analyses were conducted per a modified intention-to-treat (only complete cases for primary outcome), with sensitivity analyses using multiple imputation, per-protocol datasets and qPCR-based detection of the probiotic strains in stool (adherence). RESULTS: Fifty-six participants were included in the main analysis. Thirteen (43%) participants in the probiotic group and 17 (65%) in the placebo group achieved the primary outcome (P = 0.167). The corresponding odds ratio was 0.4 (95% CI 0.13-1.18). Patient-reported pain and global assessment were the main PASDAS components improving over time, with no between-group differences. No differences were observed in secondary clinical outcomes, gut permeability markers (zonulin, calprotectin, alpha-1-antitrypsin), immune cell profiles or stool microbiome composition between the groups at week 12. No serious adverse events related to the study product were reported. CONCLUSION: In this first RCT investigating probiotic supplementation in PsA, probiotic treatment did not show superiority over placebo in achieving treatment response, or altering gut microbiome, or permeability.

Source: Rheumatology

DOI: 10.1093/rheumatology/keag547