Until now, the exact triggers of multiple sclerosis (MS) have been elusive, with scientists suspecting an environmental factor, possibly a bacterial infection.
A new study in the Journal of Clinical Investigation now confirms that suspicion, and even identifies the responsible bacterium.
The really good news is that this also reveals a way to reverse MS.
MS is a complex condition affecting the central nervous system. It happens when our immune system attacks the protective sheath that covers nerve fibers.
This attack leads to a breakdown in communication between the brain and the rest of the body, resulting in various neurological symptoms.
In the new study, researchers recruited 62 MS patients and matched them with people of the same age, sex, body mass index, and other relevant characteristics. They asked all their subjects to provide fecal samples, which they then tested for the presence of a variety of bacteria.
They found one bacterium that was a lot more common in the feces of MS patients than in the healthy population. It is called Clostridium perfringens. While only 13% of healthy people had this in their bodies, 61% of MS patients did.
This is a relatively common bacterium found in soil and in the intestines of animals like sheep. This bacterium can make a toxin called epsilon toxin, which scientists know from previous research can break through the blood-brain barrier that usually protects our brains from toxins present in the rest of our bodies. This, they assumed, could then start the process leading to MS.
Having discovered the presence of this epsilon toxin-producing bacterium in MS patients, the scientists then consulted the scientific literature, finding the next set of facts that confirmed their theory.
In places where there are many sheep, such as in some regions of Scotland and New Zealand, the prevalence of MS is much higher than elsewhere in the world. Since this bacterium is common in sheep, this connection supports the idea that the bacteria might have something to do with MS.
The team then performed experiments with mice to see if they could replicate their findings and learn more.
They found that the epsilon toxin from the bacteria could cause brain changes in mice that were similar to what happens in humans with MS. After feeding mice these bacteria, the damage to their brains looked exactly like the damage in the human brains of people with MS, and occurred in exactly the same regions of the brain too.
The next step, which the researchers will take in subsequent studies, is to examine the cerebrospinal fluid of people with MS to see whether this toxin is present. Since this is the fluid that surrounds our brains and spinal cords, the presence of epsilon toxin there will provide irrefutable evidence of its involvement in the disease.
If you want to avoid being infected with this bacterium, the most obvious way is to thoroughly cook food, especially meat and poultry. It is also important to ensure that meat remains refrigerated, as this bacterium grows fast at room temperature. If such bacteria are involved in MS, these are the easiest ways to protect yourself against it.