Mechanism (biology)

Philosophy

Amyotrophic lateral sclerosis

Neuroscience

Biology

Endocrinology

Biochemistry

Computational biology

Evolutionary biology

Immunology

Genetics

Microbiome

Bioinformatics

Immune system

Neuroimmunology

Atrophy

Epistemology

Internal medicine

Multiple sclerosis

Gut flora

Medicine

Cell

Disease

Pathology

Short-chain fatty acids are processed from indigestible dietary fibers by gut bacteria and have immunomodulatory properties. Here, we investigate propionic acid (PA) in multiple sclerosis (MS), an autoimmune and neurodegenerative disease. Serum and feces of subjects with MS exhibited significantly reduced PA amounts compared with controls, particularly after the first relapse. In a proof-of-concept study, we supplemented PA to therapy-naive MS patients and as an add-on to MS immunotherapy. After 2 weeks of PA intake, we observed a significant and sustained increase of functionally competent regulatory T (Treg) cells, whereas Th1 and Th17 cells decreased significantly. Post-hoc analyses revealed a reduced annual relapse rate, disability stabilization, and reduced brain atrophy after 3 years of PA intake. Functional microbiome analysis revealed increased expression of Treg-cell-inducing genes in the intestine after PA intake. Furthermore, PA normalized Treg cell mitochondrial function and morphology in MS. Our findings suggest that PA can serve as a potent immunomodulatory supplement to MS drugs.

Propionic Acid Shapes the Multiple Sclerosis Disease Course by an Immunomodulatory Mechanism