A Bacterial Species Involved in Gum Disease Provokes Neuroinflammation
Researchers here provide evidence for one particular oral bacterial species associated with gum disease to provoke changes in microglia population in the brain, leading to chronic inflammation and acceleration of neurodegenerative conditions. The correlation between periodontal disease and neurodegenerative diseases such as Alzheimer's disease is well known, and there are established pathways and mechanisms for oral bacteria to deliver pro-inflammatory compounds into the body. However, some studies suggest that the contribution of gum disease to the incidence of neurodegenerative conditions is modest at best, in comparison to other factors.
Fusobacterium nucleatum (F. nucleatum) is a common type of bacteria that proliferates in periodontal disease. F. nucleatum can also generate severe generalized inflammation, which is a symptom of many chronic diseases including type 2 diabetes and Alzheimer's disease. The latest research, done in mice, shows that F. nucleatum results in an abnormal proliferation of microglial cells, which are immune cells in the brain that normally remove damaged neurons and infections and help maintain the overall health of the central nervous system. This over-supply of microglial cells also created an increased inflammatory response, the researchers found. Chronic inflammation or infection is believed to be a key determinant in the cognitive decline that occurs as Alzheimer's disease progresses.
Possible links between periodontal disease and Alzheimer's have been posited by scientists in the past. While the new research does not show that F. nucleatum-related periodontal disease leads directly to Alzheimer's disease, the new study suggests that periodontal disease caused by F. nucleatum and left untreated or poorly treated could exacerbate symptoms of Alzheimer's disease. Conversely, treating periodontal disease effectively in those who have early-stage Alzheimer's could potentially slow Alzheimer's progression.
Link: https://now.tufts.edu/2022/07/11/studying-link-between-gum-disease-and-alzheimers-disease