Bacteria Infecting Gums Can Cause Alzheimer's Disease

2023 Author: Abraham Higgins | [email protected]. Last modified: 2023-11-27 23:16

Bacteria Infecting Gums Can Cause Alzheimer's Disease

Scientists say bacteria that cause gum disease and periodontal tissue disease may play a significant role in the development of Alzheimer's disease. This finding could potentially contribute to the emergence of drugs for the disease.

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Porphyromonas gingivalis bacteria is one of the main causes of gum disease and tooth loss, but it can also damage arteries. There have been previous suggestions that it may play a role in the development of Alzheimer's disease, and new research by an international team of scientists confirms this assumption. The findings are published in the latest issue of Science Advances.

The scientists made the discovery after analyzing brain tissue, cerebrospinal fluid and saliva, both dead and living patients with diagnosed or suspected Alzheimer's disease. In the samples studied, the authors found toxic enzymes gingipain, which are secreted by the bacteria P. gingivalis, as well as the DNA of these bacteria. In addition, it has been found that in mice, this infection spreads from the mouth to the brain. Animal studies have confirmed that gingipain destroys neurons in the brain.

There is good news, however: Scientists have tested drugs that block gingipain and found they can stop neurodegenerative diseases.

One such drug, which was added to food in mice, was effective in treating P. gingivalis infections in the brain and in preventing the loss of memory neurons. Currently, a group of scientists has developed a new drug called COR388, which better penetrates the central nervous system and may become the basis for the treatment of Alzheimer's disease in humans.

Large-scale clinical trials, which will include prescribing the drug to patients with mild to moderate Alzheimer's disease, are scheduled for later this year.

Dr. Stephen Dominy, one of the study authors and developers of COR388, said that it was previously known about the involvement of infectious agents in the development and progression of Alzheimer's disease, but a causal relationship has not been convincingly proven.

Scientists examined over 50 brain tissue samples and found that 96% contained one type of gingipain and 91% another type. Further DNA testing found the P. gingivalis hmuY gene in the brains of three dead Alzheimer's patients. The same gene was also found in cerebrospinal fluid in 7 out of 10 living patients diagnosed with Alzheimer's disease. Saliva samples from 10 patients with suspected Alzheimer's disease also showed the presence of the P. gingivalis gene.

Studies in mice have shown that blocking gingipains effectively protects the hippocampus, a region of the brain vital for memory, from infection with P. gingivalis. According to the researchers, these bacteria can enter the brain, attacking cells of the immune system or spreading through the nerves in the skull that run through the head and jaw.

According to the study, traditional broad-spectrum antibiotics would be ineffective against P. gingivalis in the brain. In laboratory experiments, antibiotics did not prevent the death of cells infected with P. gingivalis. It has also been shown that the causative agent rapidly develops resistance to the broad spectrum antibiotic moxifloxacin, but not to COR388.