Gingival bacterial imbalance associated with Alzheimer’s disease biomarkers

Elderly people who have more harmful bacteria than healthy bacteria in their gums may have evidence of amyloid beta (an important biomarker for Alzheimer’s disease) in cerebrospinal fluid (CSF), according to a new study by NYU College of Dentistry and Weill Cornell. The sex will be higher. medicine. However, this imbalance of oral bacteria was not associated with another biomarker of Alzheimer’s disease called tau.

Studies published in the journal Alzheimer’s disease and dementia: diagnosis, evaluation, disease monitoringIn addition to the growing evidence of the relationship between periodontal disease (gum disease) and Alzheimer’s disease. The CDC estimates that periodontal disease, which affects 70% of adults over the age of 65, is characterized by chronic and systemic inflammation, with bacterial spread and lurking between the teeth and gums.

“As far as we know, this is cognitively normal with the disproportionate bacterial community found under periodontal disease by Dr. Angela Kammer (DDS, PhD), an associate professor of periodontal disease and implants. The first study to show an association with CSF biomarkers of Alzheimer’s disease in the elderly. Leading author of the NYU College of Dentistry Dentistry and Study. “The mouth is healthy and protective with harmful bacteria that promote inflammation. Both are inhabited. Evidence of amyloid in the brain has been found to be associated with an increase in harmful bacteria and a decrease in beneficial bacteria. “

Alzheimer’s disease is characterized by two characteristic proteins in the brain. Amyloid beta is thought to be the first protein that aggregates to form plaques and deposits in the brain at the onset of Alzheimer’s disease. Tau accumulates in nerve cells and forms entanglements.

“Cerebral amyloid levels accumulate and the mechanisms associated with Alzheimer’s disease are complex and only partially understood. In this study, pro-inflammatory diseases are amyloid from the brain as retention of amyloid in the brain. It supports the understanding that it interferes with the clearance of the disease. It can be estimated from the CSF level, “said the lead author of the study, a professor of neuroscience in radiology, and the Brain Health Imaging Institute of Weil Cornell Medicine. Director Monnie J. Deleon said. “Amyloid changes are often observed decades before Tau’s condition or symptoms of Alzheimer’s disease are detected.”

The researchers studied 48 healthy, cognitively normal adults over the age of 65. Participants underwent oral examination to collect bacterial samples from below the gingival line and obtained CSF using lumbar puncture to determine levels of amyloid beta and tau. To estimate the expression of Alzheimer’s disease proteins in the brain, researchers have low levels of amyloid beta in CSF (meaning high levels of amyloid in the brain) and high levels of tau (in the brain). It reflects the high accumulation of tangles).

Under the guidance of NYU Dental College microbiologist Deepak Saxena, PhD, the researchers analyzed bacterial DNA from samples taken from below the gingival line, and researchers found it harmful to oral health (Prevotella, Porphyromonas, Fretibacterium, etc.) and preoral health. We have quantified the bacteria known to be. Bacteria (eg Corynebacterium, Actinomyces, Capnocytophaga).

The results showed that individuals with an imbalance of bacteria at a rate detrimental to healthy bacteria were more likely to have the characteristic of Alzheimer’s disease, which is a decrease in CSF amyloid levels. Researchers assume that high levels of healthy bacteria help maintain bacterial balance and reduce inflammation, so they may be protective against Alzheimer’s disease.

“Our results show the importance of the overall oral microbiome in the role of” good “bacteria as well as” bad “bacteria in regulating amyloid levels,” says Kamer. “These findings suggest that multiple oral bacteria are involved in the development of amyloid lesions.”

The researchers did not find an association between gingival bacteria and tau levels in this study, so it is unclear whether tau lesions will develop later or if subjects will develop symptoms of Alzheimer’s disease. Researchers are longitudinal to test whether improving gum health through “deep cleaning” to remove plaque and tartar deposits from under the gums can modify cerebral amyloids and prevent Alzheimer’s disease. We plan to conduct research and clinical trials.

###

Additional study authors include Smruti Pushalkar, Deepthi Gulivindala, and Kumar Raghava Chowdary Annam of New York University School of Dentistry. Tracy Butler, Yi Li, Lydia Glogic, Karla V Ballman of Weil Cornell Medicine. Patricia Corby of the University of Pennsylvania School of Dentistry. Kaj Blennow of Gothenburg University and Saar Glenska University; Henrik Zetterberg of Gothenburg University, Saar Glenska University, UCL.

This study included the National Institutes of Health’s National Institute on Aging (AG035137, AG032554, AG12101, AG022374, AG13616, RF1AG057570, R56AG058913), the National Institute for Advancing Dental Craniotomy (DE023139), and the National Center for Advancing Translational Sciences (UL1 TR000038). ), And the Alzheimer’s Association (NIRG-12-173937).

About NYU College of Dentistry

Founded in 1865, NYU College of Dentistry is the third oldest and largest dental school in the United States, educating nearly 10% of US dentists. NYU Dentistry has a very diverse student body and is expanding globally.visit http: // dental.nyu.edu For many.

Disclaimer: AAAS and Eurek Alert! We are not responsible for the accuracy of news releases posted to EurekAlert! To use the information by contributing to the institution or through the Eurek Alert system.