The causes of multiple sclerosis (MS) have remained unclear despite decades of research. But new findings have linked this debilitating disease to a toxin produced by some strains of the bacteria that causes food poisoning.

Based on their findings in mice and MS patients, the investigators believe that the epsilon toxin produced by Clostridium perfingens bacteria can act as an environmental trigger, causing the disease to develop in people who are already genetically susceptible. C. perfingens, which is found in raw meat and soil, is estimated to cause nearly a million cases of food poisoning annually from undercooked meat. But only a fraction of C. perfingens produce epsilon toxin: when the research team tested 37 food samples, they found C. perfingens in five samples (13.5%), but epsilon toxin in only one (2.7%). In the brains of mice, epsilon toxin targeted a specific set of cell types identical to those damaged in people with MS. MS affects an estimated 250,000–300,000 Americans, and typically begins with symptoms including numbness in the arms and legs, dizziness and vision problems that can ultimately lead to paralysis and blindness. It is hoped that the identification of epsilon toxin as a trigger can help in the development of treatments to stop the disease from progressing or even prevent it from starting.

(Source: Proceedings of the 2014 American Society for Microbiology Biodefense and Emerging Diseases Research Meeting, Washington D.C. Photo of laboratory-grown Clostridium perfingens courtesy of Flickr; Nathan Reading)