Researchers have uncovered a novel connection between two neurodegenerative disorders. This research, which was published in Cell Reports, found that gut bacteria are linked to the neurodegeneration that occurs in both amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD) The work showed that certain sugars that are produced by gut bacteria can trigger immune responses that destroy neurons. Since this study also identified a potential way to prevent this from happening, it could eventually lead to better treatments for both disorders.
In FTD, the primary impacts are seen in the frontal and temporal lobes of the brain. This leads to significant changes in a patient's behavior, personality, and language abilities. In ALS, motor neurons are affected, and there is major deterioration in a patient’s ability to move and function.
The causes of both disorders are still unclear, although genetics and environmental factors seem to influence them, along with brain injuries.
This study showed that certain harmful gut microbes generate a type of sugar known as glycogen, which can lead to immune responses that interfere with the brain, said senior study author Aaron Burberry, assistant professor at Case Western Reserve University School of Medicine.
This can explain why certain genetic mutations lead to FTD or ALS in some people, but not others–gut bacteria seem to be the trigger.
There were 23 people with ALS or FTD assessed for this study, and 70% of them carried dangerously levels of glycogen levels. But these unusually high glycogen levels were only seen in about 30% of people without neurodegenerative disease.
If confirmed, these findings could improve ALS and FTD patient care, and reveal biomarkers that can be used to show who may benefit from therapeutics that take aim at gut microbes. It may be possible to develop drugs that can degrade harmful sugars before they damage brain cells.
“To understand when and why harmful microbial glycogen is produced, the team will next conduct larger studies surveying gut microbiome communities in ALS/FTD patients before and after disease onset,” Burberry said. “Clinical trials to determine whether glycogen degradation in ALS/FTD patients could slow disease progression are also supported by our findings and could begin in a year.”
Sources: Case Western Reserve University, Cell Reports
