New research suggests a possible shift in how Alzheimer’s disease is understood, treated, and prevented
Scientists believe they may have uncovered a connection between a common viral gut infection and the later development of a particular form of Alzheimer’s disease.
Researchers from Arizona State University and Banner Alzheimer’s Institute have made what they consider a significant breakthrough in understanding the disease.
Alzheimer’s, in all its variations, is particularly devastating because it gradually robs individuals of their ability to think and remember.
Brain’s immune cells, light blue and purple, shown interacting with amyloid plaques, red, linked to Alzheimer’s disease
Jason Drees/Arizona State University
A person can go from being fully functional to struggling with basic cognitive tasks within just a few years. Sadly, this disease is ultimately fatal.
Their findings were recently published in the journal Alzheimer’s & Dementia, and the researchers believe that uncovering this connection between gut infections and Alzheimer’s could play a key role in developing better ways to treat and prevent the disease.
What is the virus?
Most people are believed to come into contact with this virus—cytomegalovirus (HCMV)—within the first few decades of life.
HCMV belongs to the herpes virus family, though unlike some other herpes viruses, it is not classified as a sexually transmitted infection.
According to this research, in some individuals, the virus may persist in the gut, causing a chronic infection that lingers in the body over time.
How does HCMV relate to Alzheimer’s disease?
Over time, the virus may travel to the brain through the vagus nerve—an essential pathway that connects the gut and the brain.
Once inside the brain, the virus is believed to trigger changes in the immune system that contribute to key characteristics of Alzheimer’s disease.
When it reaches brain tissue, the virus prompts immune cells known as microglia to activate a gene called CD83.
Previous studies have already linked this gene to Alzheimer’s, making this discovery especially significant.
What do these findings mean?
Dr. Ben Readhead, one of the study’s co-founders, discussed the significance of the research and its potential implications.
Alzheimer’s is known to be a particularly brutal and fatal disease
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He said: “We think we found a biologically unique subtype of Alzheimer’s that may affect 25-45 per cent of people with this disease.”
While further research is required to confirm these findings, this study could pave the way for new approaches to preventing Alzheimer’s before symptoms even begin.
In the long run, scientists hope that existing antiviral medications could be repurposed to help treat or prevent this specific form of the disease.
Researchers believe that newly developed blood tests could help identify individuals who have an active HCMV infection.
Dr. Readhead added: “This subtype of Alzheimer’s includes the hallmark amyloid plaques and tau tangles — microscopic brain abnormalities used for diagnosis – and features a distinct biological profile of virus, antibodies and immune cells in the brain.”