Acetate correlates with disability and immune response in multiple sclerosis

Gut microbiota has been related to multiple sclerosis (MS) etiopathogenesis. Short-chain fatty acids (SCFA) are compounds derived from microbial metabolism that have a role in gut-brain axis. Our aim was to analyse SCFA levels in plasma of MS patients and healthy donors (HD), and the possible link between these levels and both clinical data and immune cell populations. 97 MS patients and 55 HD were recruited. Patients were selected according to their EDSS (50 EDSS≤1.5, 47 EDSS≥5.0). SCFA were studied in plasma samples by liquid chromatography-mass spectrometry. Peripheral blood mononuclear cells were studied by flow cytometry. Gender, age, treatments, EDSS and MSSS were evaluated at the recruitment. Plasma acetate levels were higher in patients than in HD (p=0.003). Patients with EDSS≥5.0 had higher acetate levels than those with EDSS≤1.5 (p=0.029), and HD (p=2.97e-4). Acetate levels correlated with EDSS (r=0.387;p=1.08e-4) and MSSS (r=0.265;p=0.011). In untreated MS patients, acetate levels correlated inversely with CD4+ naïve T cells (r=-0.550,p=0.001) and directly with CD8+ IL-17+ cells (r=0.557;p=0.001). We conclude that plasma acetate levels are higher in MS patients than in HD. In MS there exists a correlation between plasma acetate levels, EDSS and increased IL-17+ T cells. Future studies will elucidate the role of SCFA in the disease.