Researchers at Mayo Clinic in Rochester haven’t reached their goal of proving that a bacteria in the human gut causes celiac disease.
But in a bit of good fortune, they might have stumbled upon one that is implicated in multiple sclerosis.
In a report earlier this month, Dr. Joseph Murray and colleagues from Mayo and the University of Iowa detailed their unexpected finding — that one of a series of poorly understood gut microbes known as Prevotella bacteria might inhibit the immune system’s role in causing multiple sclerosis.
“There are bugs that work within the gut but affect parts of the body way beyond the gut,” said Murray, a gastroenterologist. “One in particular seems to suppress the inflammatory response in the immune system.”
The researchers tested the bacteria on a mouse model of multiple sclerosis, a degenerative disease in which the immune system weakens the protective coating around the brain and spinal cord and causes severe physical disabilities.
The bacteria boosted growth of regulatory cells that act “like the FBI” and discern when the immune system needs to attack, Murray said. They also appeared to play a role in tightening the protective blood-brain barrier that gets weakened by MS.
Murray said the Prevotella bacteria is difficult to grow and work with, but could one day become one of the first “brugs” — a composite term he coined to describe a bacteria that would be administered to patients like a prescription drug.
The initial findings were published in the scientific journal Cell Reports, but follow-up studies and clinical tests on humans would be needed before such a treatment could receive federal safety approval.
The specific bacteria, named P. histicola, appears to be one of the “good” bugs that supports digestion and moderates the immune system, Murray said. He theorized that it played a role in celiac disease, an autoimmune disorder that disrupts digestion and the small intestine, before he credited “open minds” of colleagues for exploring its link to MS as well.
The bacteria also might have an impact on rheumatoid arthritis, another autoimmune disease that attacks the joints.