Short-chain fatty acid charts multiple sclerosis disease course

Propionic acid, a short-chain fatty acid, influences the intestine-mediated immune regulation in patients with multiple sclerosis (MS), according to new research published in the journal Cell.

The application of propionic acid in addition to MS medication reduced the relapse rate and the risk of disability progression in the long-term. Moreover, initial Magnetic Resonance Imaging (MRI) studies indicated that propionic acid may reduce brain atrophy as a sign of neuronal cell death, the researchers said.

The gut microbiome has been associated with chronic diseases, such as MS. Within the gut, the interaction between dietary components, microbiota, metabolites, and the immune system takes place in the intestinal wall.

For the study, led by researchers at Ruhr-Universität Bochum in Germany, the researchers successfully transferred the results previously shown in the cell culture dish and the experimental model to their MS patients. Short-chain fatty acids such as propionic acid or its salt propionate increased the differentiation and function of regulatory T cells in the gut.

In collaboration with researchers from the Bar-Ilan University in Israel, who had developed an intestinal model for the functional analysis of the microbiome, the researchers found propionate-associated changes of the gut microbiome play a crucial role in the differentiation of regulatory cells. The increased function of these cells was due to their improved energy utilization through an altered function of the mitochondria, the study said.  

The researchers showed that the microbiome composition is altered in MS patients. The results demonstrated a deficiency of propionic acid in the feces and serum of MS patients, which was most pronounced in the earliest phases of the disease.

The short-chain fatty acids represent a fraction of the metabolites of intestinal bacteria that are generated from the diet, according to Aiden Haghikia, lead author of the study and professor at Ruhr-Universität Bochum.

“Further research into this largely unknown organ,” he said in a statement, “and the knowledge gained from it will enable us to develop innovative dietary measures to complement the known therapeutics in the future.”