# Bacterial links to Alzheimer’s disease risk

> Live situation record from CLSTR: https://clstr.news/situations/bacterial-links-to-alzheimers-disease-risk
> Updated: 2026-08-25T11:52:59.000Z. Sources: 4. Developments: 2.

Research indicates that poor oral hygiene and the presence of the bacterium Porphyromonas gingivalis may serve as biological risk factors for Alzheimer’s disease. This pathogen, which is associated with chronic periodontitis, can breach the blood-brain barrier and release toxins into brain tissue.

Studies have identified the presence of P. gingivalis in over 90% of analyzed brains belonging to Alzheimer’s patients. The toxins produced by these bacteria are linked to neuronal damage markers, such as the tau protein, while the brain may accumulate amyloid plaques as a defensive response to the bacterial invasion. Because oral infections can trigger systemic chronic inflammation and accelerate cognitive decline, maintaining dental hygiene is identified as a modifiable risk factor to help protect the nervous system.

## Timeline

### 2026-08-25: Poor oral hygiene linked to increased Alzheimer's risk

Poor oral hygiene and the bacterium Porphyromonas gingivalis are linked to increased Alzheimer's risk by causing brain inflammation and breaching the blood-brain barrier.

2 sources. https://clstr.news/cluster/poor-oral-hygiene-linked-to-increased-alzheimers-risk

### 2026-08-23: Scientific studies link bacteria to psychopathy and pollution to Alzheimer's

New studies link gut and oral bacteria to psychopathic traits and reveal how air pollution triggers chemical changes in the brain that may contribute to Alzheimer's and memory loss.

2 sources. https://clstr.news/cluster/scientific-studies-link-bacteria-to-psychopathy-and-pollution-to-alzheimers

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Cite as: Bacterial links to Alzheimer’s disease risk. CLSTR, https://clstr.news/situations/bacterial-links-to-alzheimers-disease-risk