Mouth Bacteria May Be Linked to Parkinson’s Disease

South Korean researchers have found that bacteria from the mouth may travel to the gut and help trigger Parkinson’s disease.

The study, published in Nature Communications, found higher levels of Streptococcus mutans—a common cause of tooth decay—in the guts of people with Parkinson’s. This bacterium produces a chemical called ImP, which can enter the bloodstream, reach the brain, and damage nerve cells that control movement.

When researchers introduced these bacteria or their chemicals into mice, the animals developed Parkinson’s-like symptoms, including brain inflammation and movement problems. Blocking a brain signal pathway called mTORC1 helped reverse these effects.

Scientists say the discovery shows how bacteria from the mouth can influence the brain, opening the door to new treatments that target gut microbes to help prevent or manage Parkinson’s disease.