Multiple sclerosis (MS) could be triggered by a toxin from food-borne bacteria.
MS is "an inflammatory disease of the central nervous system characterized by blood brain (BBB) permeability and demyelination, a process in which the insulating myelin sheaths of neurons are damaged," an American Society for Microbiology news release reported.
The condition is the most frequent cause of neurological disability in the U.S. excluding trauma; it affects about 400,000 Americans.
The disease is believed to be genetic, but triggered by environmental factors; now researchers have linked it with a toxin that is commonly found in food items.
"We provide evidence that supports epsilon toxin's ability to cause BBB permeability and show that epsilon toxin kills the brain's myelin producing cells, oligodendrocytes; the same cells that die in MS lesions," Jennifer Linden of Weill Cornell Medical College, who presented the research, said in the news release. "We also show that epsilon toxin targets other cells types associated with MS inflammation such as the retinal vascular and meningeal cells. Epsilon toxin may be responsible for triggering MS."
The toxin is produced by certain strains of the bacterium Clostridium perfringens, which is the key cause of foodborne illness in the U.S., it is believed to cause about a million cases of foodborne illness annually.
Past studies have suggested C. perfringens is connected with MS; last year the researchers observed C. perfringens type B (which produces the epsilon toxin but has not been known to infect humans) in a 21-year-old woman suffering from an MS flare up.
This discovery prompted researchers to observe which cells the toxin targeted in mice.
"Originally, we only thought that epsilon toxin would target the brain endothelium cells and oligodendrocytes; we just happened to notice that it also bound to and killed meningeal cells. This was exciting because it provides a possible explanation for meningeal inflammation and subpial cortical lesions exclusively observed in MS patients, but not fully understood," Linden said.
The team also tested local groceries for the bacteria and toxin. Out of 37 food samples 13.5 percent tested positive for the bacteria and 2.7 percent contained the epsilon toxin gene.
The finding could lead to the development of vaccine against the MS-related toxin.
