New Blood Test Spots Alzheimer's 16 Years Before Symptoms Develop

These findings indicate that lack of sleep alone helps drive the disease and suggests that good sleep habits may help preserve brain health.

Researchers at Cortexyme, a San Francisco pharmaceutical company, are looking into a potential drug to block the gum bacteria's apparent effects in the brain.

And when they watched P. gingivalis infections play out in mice, it triggered neurodegeneration in the hippocampus, a brain structure central to memory.

New research identified P. gingivalis, the same bacteria responsible for gum disease, as the possible culprit behind Alzheimer's disease.

It's possible that news of the possible link will lead to people spending more time on their dental health than they now do, though: One study found less than one third of Americans floss daily.

When the team gave P. gingivalis gum disease to mice, it led to brain infection, amyloid production, tangles of tau protein, and neural damage in the regions and nerves normally affected by Alzheimer's. However, looking at the presence of bacteria in human brain tissue doesn't tell us anything about whether this may have a role in causing the disease. Another physical characteristic of the Alzheimer's diseased brain is the buildup of tau proteins, which tangle inside neurons, blocking their transport system.

The researchers studied more than 400 people participating in the DIAN study, 247 who carry an early-onset genetic variant and 162 unaffected relatives. In both mice and human brain tissue, scientists discovered a drop in receptors for glutamate, a neurotransmitter in the brain necessary for both learning and short-term memory retention.

"We now have strong evidence connecting P. gingivalis and Alzheimer's pathogenesis, but more research needs to be done before P. gingivalis is explicitly implicated in the causation or morbidity of Alzheimer's disease", said study co-author Jan Potempa.

In mouse studies, oral infection with the same bacteria led to colonisation of the brain.

Although there is still no cure for Alzheimer's disease, the possibility of treating the condition more than a decade before it develops opens a world of new possibilities.

Prof Tara Spires-Jones, from the UK Dementia Research Institute, at the University of Edinburgh, said it was "great news" that the study provided evidence these drugs may affect Alzheimer's-related proteins. And, in follow-up studies in the mice, the research team has shown that sleeplessness accelerates the spread through the brain of toxic clumps of tau - a harbinger of brain damage and decisive step along the path to dementia.

Alzheimer's is caused by gene expression changes that happen later in life, but little is known about how they occur.

Earlier this week, researchers from Washington State University announced the development of a new kind of blood test that seems to be able to predict onside of the disease as long as 16 years before symptoms actually emerge. Later this year the firm will launch a larger trial of the drug, looking for P. gingivalis in spinal fluid, and cognitive improvements, before and after. In the United Kingdom, 850,000 people live with dementia, according to the Alzheimer's Society. Alzheimer's constitutes some 70 per cent of these cases and yet, we don't know what causes it.

The Mayo Clinic describes Alzheimer's disease as a progressive disorder that attacks the brain, causing a "continuous decline in thinking, behavioral and social skills".

  • Santos West