Therapeutic alteration of the microbiota in rheumatic diseases: Hype or potential?

Area of Science:

• Rheumatology
• Microbiome research
• Immunology

Background:

• Fecal microbiota alterations are observed in various forms of arthritis.
• Microbial-altering therapies are being explored for rheumatic diseases.
• Antibiotics are less favored; probiotics and fecal microbial transplantation (FMT) are under investigation.

Purpose of the Study:

• To review the literature on probiotics and FMT in rheumatic diseases.
• To discuss reasons for the lack of demonstrated clinical benefit.
• To suggest future research directions for microbial therapies in rheumatology.

Main Methods:

• Literature review of studies on probiotics and FMT in rheumatoid arthritis, spondyloarthritis, and systemic sclerosis.
• Analysis of clinical trial outcomes and tolerability data.
• Discussion of potential mechanisms underlying treatment efficacy or lack thereof.

Main Results:

• Probiotics were well-tolerated but showed minimal clinical benefit across indications.
• Fecal microbial transplantation (FMT) studies yielded mixed results, with one showing minimal benefit and another showing worsening symptoms.
• Current evidence suggests limited efficacy of probiotics and FMT in treating rheumatic diseases.

Conclusions:

• Despite promising rationale, probiotics and FMT have not consistently demonstrated significant clinical benefits in rheumatic diseases.
• Potential reasons for limited efficacy include heterogeneity of disease, microbial diversity, and treatment protocols.
• Future research should focus on identifying specific microbial targets, optimizing delivery methods, and conducting well-designed clinical trials.