Exposure to certain gut bacteria at a young age may cause multiple sclerosis (MS) and fuel its progression, a new mouse study shows.
The study, “Gut dysbiosis breaks immunological tolerance toward the central nervous system during young adulthood,” appeared in the journal Proceedings of the National Academy of Sciences.
In recent years, research on this autoimmune disease has focused on gut bacteria, with studies suggesting they can work as protective elements against MS. But others have shown they actually contribute to disease progression. Even so, these findings all support the hypothesis that regulating gut bacteria could represent a new potential therapy for MS.
With that in mind, researchers at New Jersey’s Rutgers Robert Wood Johnson Medical School conducted a study with mice genetically engineered to have MS-associated risk genes that had been previously identified in patients.
The team found that as long as mice were kept in a sterile, bacteria-free environment, they showed no signs of MS. However, once they were moved to a normal environment and were exposed to bacteria, they spontaneously developed experimental autoimmune encephalomyelitis (EAE), an MS-like disease.
In addition, adolescent or young adult mice were more susceptible to MS than older animals. This, say researchers, may be due to an increased immunological tolerance that mice acquire as they age.
Analysis of gut bacteria populations showed that mice that developed EAE had higher amounts of Bacteroides vulgatus but lower amounts of Akkermansia muciniphila compared to controls.
Overall, this gut bacteria imbalance triggered pro-inflammatory signals and activated immune T-cells during the age window of mice in young adulthood, further supporting the role of gut bacteria in MS onset and progression.
“The findings could have therapeutic implications on slowing down MS progression by manipulating gut bacteria,” the study’s co-author, Suhayl Dhib-Jalbut, said in a news release. Dhib-Jalbut, a neurology professor, is also director of the Rutgers-Robert Wood Johnson Center for Multiple Sclerosis.
The team won a grant from the National Institutes of Health to fund additional studies on the role of gut bacteria in MS development.