Oral Health
The mouth and the gut are closely connected. Inflammation in the mouth can burden the whole body.
Updated: October 2026
What does the research say?
Large observational studies found a link between periodontitis and a higher risk of Parkinson's. Whether this is a cause or a consequence is unclear. The tooth decay bacterium Streptococcus mutans is also under suspicion: researchers in South Korea found more of it in the gut of Parkinson's patients, and in mice a substance it produces triggered damage typical of Parkinson's (Nature Communications 2025). This has not been proven in humans (ScienceDaily). In people with Parkinson's, the inflammation marker RANTES is also often elevated in the blood, and in one study higher levels went along with a more severe course (PMC).
The common belief that root-canal-treated teeth are harmful in general is not scientifically proven.
New (2026): A review concludes that people with Parkinson's have gum problems more often, mostly because brushing becomes harder. However, it is not proven that periodontitis causes or worsens Parkinson's (Frontiers in Oral Health). Good dental care still makes sense.
My experience
In mid-2023 and again in 2026, I had a RANTES test done. RANTES is associated with hidden inflammation in the jaw. Both times the result was normal. I had my only root-canal-treated tooth replaced with a ceramic implant, because I consider dead teeth a possible burden.
My conclusion
Regular dental care and checkups at the dentist are simple and sensible. If you suspect hidden inflammation, a RANTES test can give clues.