Probiotic therapy for the treatment of spondyloarthritis: a randomized controlled trial

To investigate the effect of an orally administered probiotic on disease activity, fatigue, quality of life, and intestinal symptoms in patients with active spondyloarthritis.

Patients with active spondyloarthritis [defined as Bath Ankylosing Spondylitis Disease Activity Index (BASDAI) ≥ 3, Bath Ankylosing Spondylitis Functional Index (BASFI) ≥ 3, Maastricht Ankylosing Spondylitis Enthesitis Score (MASES) ≥ 2, or peripheral joint count ≥ 2] were randomized to oral probiotic or placebo for 12 weeks. Patients and assessors were blinded to treatment allocation. The primary outcome measure was 10% improvement in the BASFI. Additional outcome measures were improvements in the ASsessments in Ankylosing Spondylitis (ASAS)-endorsed core domains: pain, spinal mobility, patient global, peripheral joint and entheseal scores, stiffness, C-reactive protein, and fatigue. The ASAS20 criteria, a composite measure of response, were also applied. Quality of life and bowel symptoms were quantified using the Ankylosing Spondylitis Quality of Life Questionnaire (ASQoL) and Dudley Inflammatory Bowel Symptom Questionnaire (DISQ).

Sixty-three patients were randomized to oral probiotic (n = 32) or placebo (n = 31). All patients completed the trial. No significant difference was noted between groups in any of the core domains. The mean BASFI fell from 3.5 ± 2.0 to 2.9 ± 1.9 in the probiotic group and from 3.6 ± 1.9 to 3.1 ± 2.2 in the placebo group (p = 0.839). The mean BASDAI fell from 4.2 ± 2.2 to 3.2 ± 2.1 in the probiotic group and 4.5 ± 2.0 to 3.9 ± 2.2 in the placebo group (p = 0.182). No significant adverse events were recorded in the probiotic-treated group.

In this randomized controlled trial, the probiotic combination administered did not demonstrate significant benefit over placebo, despite a theoretical rationale for this therapy.