Propionic acid in multiple sclerosis: a phase 2b, double-blind, randomized placebo-controlled trial
Open Access
- 6 July 2026
- journal article
- Published by Oxford University Press (OUP) in Brain
- Vol. 149 (7) , 2286-2294
Abstract
Propionic acid (PA), a microbial-derived short-chain fatty acid, contributes to intestinal barrier integrity, systemic immune regulation, and neuronal function. Individuals with multiple sclerosis show reduced PA levels, and open-label data have suggested beneficial immunomodulatory and clinical effects of supplementation. The Multiple sclerosis And DisAbility Improvement (MADAI) trial was a randomized, double-blind, placebo-controlled, single-centre, phase 2b study designed to evaluate the efficacy and safety of PA as an add-on therapy in adults with clinically stable multiple sclerosis. Between April 5 and 29 May 2024, 101 adults (64% women; mean age 45 years) were randomly assigned in a 2:1 ratio to receive PA 500 mg twice daily or matching placebo for 90 days. The primary outcome was the change in serum neurofilament light chain (sNfL) concentration, a biomarker of neuroaxonal damage, adjusted for age, body mass index, creatinine, and baseline sNfL. Secondary outcomes included physical and cognitive performance measures and patient-reported outcomes, including fatigue and quality of life scores. sNfL levels were significantly reduced in the PA group {−17.9%; from 9.77 pg/ml [95% confidence interval (CI) 9.00 to 10.60] to 8.02 pg/ml (95% CI 7.36 to 8.73); mean difference 1.75 pg/ml (95% CI 0.9 to 2.6); P = 0.000025}, while no significant change was observed in the placebo group. The adjusted mean difference in sNfL levels between the PA and placebo groups at follow-up was 0.91 pg/ml (95% CI 0.02 to 1.79; P = 0.045). Reductions in sNfL were also observed among participants in the PA arm receiving moderate-to-high efficacy disease-modifying therapies (n = 41; P = 0.0001), including those on anti-CD20 treatment (n = 27; P = 0.0005). There was a trend towards improvement in motor fatigue in the PA group. No serious adverse events related to the study medication occurred. PA supplementation was well tolerated and associated with significant reductions in sNfL, suggesting attenuation of neuroaxonal injury in multiple sclerosis. These findings support further evaluation of PA as an add-on treatment in larger, long-term studies.Keywords
Funding Information
- ZeinPharma
- KME Germany (64569)
This publication has 34 references indexed in Scilit:
- The role of serum neurofilament light (sNfL) as a biomarker in multiple sclerosis: insights from a systematic reviewJournal of Neurology, 2025
- Global, regional, and national burden of disorders affecting the nervous system, 1990–2021: a systematic analysis for the Global Burden of Disease Study 2021The Lancet Neurology, 2024
- Guidance for use of neurofilament light chain as a cerebrospinal fluid and blood biomarker in multiple sclerosis managementEBioMedicine, 2024
- Blood neurofilament light levels predict non-relapsing progression following anti-CD20 therapy in relapsing and primary progressive multiple sclerosis: findings from the ocrelizumab randomised, double-blind phase 3 clinical trialsEBioMedicine, 2023
- Emerging imaging and liquid biomarkers in multiple sclerosisEuropean Journal of Immunology, 2023
- Association of Serum Neurofilament Light Chain Levels at Disease Onset With Disability Worsening in Patients With a First Demyelinating Multiple Sclerosis Event Not Treated With High-Efficacy DrugsJAMA Neurology, 2023
- Microbial-derived metabolites induce actin cytoskeletal rearrangement and protect blood-brain barrier functioniScience, 2022
- Serum neurofilament light chain for individual prognostication of disease activity in people with multiple sclerosis: a retrospective modelling and validation studyThe Lancet Neurology, 2022
- Contribution of Relapse-Independent Progression vs Relapse-Associated Worsening to Overall Confirmed Disability Accumulation in Typical Relapsing Multiple Sclerosis in a Pooled Analysis of 2 Randomized Clinical TrialsJAMA Neurology, 2020
- Propionic Acid Shapes the Multiple Sclerosis Disease Course by an Immunomodulatory MechanismCell, 2020