University of Louisville researcher Jan Potempa, Ph.D., Department of Oral Immunology and Infectious Diseases in the School of Dentistry, was part of the team of worldwide scientists led by Cortexyme Inc., a privately held, clinical-stage pharmaceutical company.
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. The treatment recently passed human safety studies and is due to enter Phase II/III clinical trials in mild to moderate Alzheimer's patients this year. A survey conducted by the US Centers for Disease Control and Prevention indicated that five (5) million American's are living with Alzheimer's, the most common form of dementia.
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.
The fact that other conditions - like brain damage or multiple sclerosis - will also raise NfL levels complicates the test.
Alzheimer's is caused from both genetic and environmental risk factors, such as ageing, which combine to result in epigenetic changes, leading to gene expression changes, but little is known about how that occurs.
"The idea that bacteria and viruses may play a part in brain disease like Alzheimer's is not necessarily new", Rebecca Edelmayer, Ph.D., director of scientific engagement for the Alzheimer's Association, told CBS News.
The team detected the organism's toxic proteases, or gingipains, in the neurons of patients with Alzheimer's disease. Since the study's publication, the neurologists are planning to expand their research to include more patients.
At the same time they discovered the link between the pathogenic mouth bacteria and Alzheimer's disease still needs further study.
In the United Kingdom, there are 850,000 people living with dementia, Alzheimer's disease is the most common type of this condition, according to the Alzheimer's Society in the UK.
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".
Gum disease affects an estimated 45% of the United Kingdom population, according to the British Dental Association (BDA).
In separate experiments with mice, oral infection with the pathogen led to brain colonisation by the bacteria, together with increased production of amyloid beta (Aβ), the sticky proteins commonly associated with Alzheimer's.
The antibiotic reduced the amount of bacteria in infected mice and stopped the formation of amyloid beta plaques while reducing inflammation, the team reports Wednesday in the journal Science Advances.
Trying to stop Pg buildup, the team designed small molecule inhibitors targeting the toxic enzyme gingipains.
"The findings of this study offer evidence that P. gingivalis and gingipains in the brain play a central role in the pathogenesis [development] of AD [Alzheimer's disease], providing a new conceptual framework for disease treatment", the study authors write.
The findings, which were published in the January 14 issue of Nature Medicine, can potentially help with early Alzheimer's diagnoses and new drug development.
"We collect blood, spinal fluid and urine to try and look for ... what people like to call biomarkers of Alzheimer's disease", said Michael Harrington, a director of neuroscience and research at HMRI.
Of the many changes in the brain which precede the disease's symptoms, one change is also the accumulation of NfL in the blood before any symptoms begin, said Jucker.