People with poor oral be at higher risk of developing Alzheimer's compared with those who have healthy mouths, according to recent research from the University of Central Lancashire (UCLan). The presence of porphyromonas gingivalis in the brains of patients who had dementia when they were alive. The bacterium is usually associated with chronic periodontal disease. The study, published in the Journal of Alzheimer's Disease, looked at 10 brain samples from patients with dementia which were donated for analysis by a scheme called Brains for Dementia Research, alongside 10 brain samples from people who had not had the. Examination of the samples revealed the presence of the porphyromonas gingivalis in the samples of the brains affected by Alzheimer's. These bacteria are usually found in oral cavities, and enter the blood stream through chewing, eating and brushing teeth. However, it is more likely to enter the blood stream after invasive dental treatment, where it is possible that the bacteria can enter the brain regularly, the researchers say. Each time the bacteria enter the brain, the researchers note, this could potentially trigger immune system responses, causing the release of excess chemicals that can kill neurons. The researchers say that this activity could lead to symptoms such as confusion and deteriorating memory - typical symptoms of Alzheimer's disease.