Researchers may have unearthed a trigger for multiple sclerosis (MS) that’s been hiding in plain sight. Scientists from Weill Cornell Medical College and Rockefeller University have identified a bacterium they believe can trigger MS—and it’s found just about everywhere, including dirt.
Their study, published in PLOS ONE, is the first to identify the bacterium, Clostridium (C.) perfringens type B, in humans. They first identified it in the blood of a 21-year-old woman with MS who was having a relapse.
She was part of the Harboring the Initial Trigger for MS (HITMS) observational study launched by Timothy Vartanian, a professor of neurology and neuroscience at Weill Cornell Medical College and director of the Judith Jaffe Multiple Sclerosis Center at New York-Presbyterian Hospital and Weill Cornell, and Kareem Rashid Rumah, an MD/PhD student at Weill Cornell and lead investigator.
Getting the Dirt on C. perfringens
C. perfringens, found in soil, is one of the most common types of bacteria in the world. It has five subsets, A through D. Type A commonly occurs in the human gastrointestinal tract and is thought to be harmless. Types B and D, however, can emit a harmful substance called epsilon toxin when eaten by grazing livestock. The substance travels through the bloodstream, crossing the blood-brain barrier and destroying myelin, causing MS-like symptoms in the animals.
Vartanian, Rashid, and their team wondered if C. perfringens types B or D could be identified in humans. They tested the blood of both MS patients and healthy control subjects. In samples from MS patients, the levels of antibodies to the toxins were 10 times higher than in the healthy controls. They also noted that only one sample in 100 from the healthy controls showed any sign of exposure to the bacteria.
Researchers hypothesize that eating grazing animals who are infected with the bacteria could be the way C. perfringens Type B is introduced into the human digestive system.
The human gut plays host to many types of bacteria, not all of them bad. Some are actually necessary for maintaining good health. Researchers suppose that the reason one person reacts to the toxin emitted by the bacteria while another does not may depend on the natural balance of bacteria in a person’s gut.
“We believe the toxin enters the blood from the gut,” said Vartanian in an interview with Healthline. “Once in the blood, the toxin binds to a specific receptor present on the [lining of] the brain blood vessels, resulting in injury to the blood brain barrier (BBB). The toxin in the blood can then enter the brain at focal sites of BBB injury and bind to the same receptor on oligodendrocytes, the myelin forming cells of the central nervous system, resulting in oligodendrocyte death.”
The type B bacteria, once settled in the gut, goes through growth cycles followed by periods of dormancy. Since the toxin is only emitted during active periods, it is not always present in the bloodstream.
Researchers are intrigued by this cyclical activity and hope to investigate whether these growth cycles coincide with relapses in people with relapsing-remitting forms of MS.
“We are working on that now and need funding to push this project faster,” said Vartanian. The findings of this small study are exciting, but must be replicated by other researchers.
Could the immune response seen in MS patients in fact be caused by the body’s attempt to fight the toxin? According to the researchers, it’s possible.
“Our hypothesis,” said Vartanian, “is that new lesion formation is driven by epsilon toxin solely. We postulate that in genetically susceptible people, secondary immune responses lead to the inflammatory response. This may be autoimmune or this may be secondary inflammation. We remain open to all possibilities.”
How Can We Avoid the Bacteria?
While a vaccine for cattle exists, the researchers don't know whether our food supply is protected by regular vaccinations of livestock. Calls made by Healthline to the U.S. Department of Agriculture were not returned.
According to drug maker Novartis, which produces the animal vaccine, their Clostri Shield 7 “is proven effective against a broad spectrum of clostridial bacteria,” including “C. perfringens Types B, C, and D.” But the vaccine does not appear to be federally mandated.
While cooking may kill the bacteria, Vartanian said, “neither cooking nor pasteurization will kill the spores.” So, there’s no foolproof method of avoiding exposure if you eat meat.
Perhaps Dr. Roy L. Swank, who authored The Multiple Sclerosis Diet Book more than 40 years ago was onto something. According to the book, eating red meat for the first year of the diet is strictly forbidden.
Food For Thought
Although this study seems to connect many of the MS dots, there is still much more work to be done. Conjecture and speculation, unless backed by trial data, are just guess work.
“Rashid and I are at once cautious and enthusiastic about our work,” said Vartanian. “We do not want to make claims that we have not justified with research. Right now, epsilon toxin remains an attractive candidate for causing new lesion formation in MS and triggering the disease. We have miles to go, however, before proving this.”
This study opens up a whole new approach to understanding MS. And, if it turns out that epsilon toxin is indeed an MS trigger, a human vaccine to protect against C. perfringens could be an easy leap from the vaccine that already exists.