Most people think of brushing their teeth as a way to avoid cavities and keep their breath fresh. But new research suggests that oral hygiene may be far more important than we once thought.
A recent study from South Korea has found evidence that bacteria from the mouth can travel into the gut and may play a role in the development of Parkinson’s disease, a serious brain disorder that affects movement.
The study was carried out by a large research team from POSTECH, Sungkyunkwan University School of Medicine, and Seoul National University College of Medicine. Their work was published in the journal Nature Communications.
Together, the scientists uncovered a biological link between oral bacteria, gut activity, and damage to brain cells that are affected in Parkinson’s disease.
Parkinson’s disease is a long-term condition that mainly affects older adults. It causes symptoms such as shaking, muscle stiffness, slow movement, and balance problems.
Over time, it can make daily activities very difficult. Around one to two percent of people over the age of 65 develop Parkinson’s, and there is currently no cure. Treatments can help manage symptoms, but they do not stop the disease from getting worse.
For many years, scientists believed Parkinson’s disease started only in the brain. More recently, research has suggested that the gut may also play an important role. People with Parkinson’s often have digestive problems years before movement symptoms appear.
Studies have also shown that the mix of bacteria living in the gut of Parkinson’s patients is different from that of healthy people. However, it was not clear which bacteria were involved or how they could affect the brain.
In this new study, researchers focused on a common mouth bacterium called Streptococcus mutans. This bacterium is well known for causing tooth decay and cavities.
The team discovered that people with Parkinson’s disease had higher levels of this bacterium in their gut than healthy individuals. This finding was surprising because S. mutans usually lives in the mouth, not the intestines.
The researchers found that Streptococcus mutans produces an enzyme that leads to the creation of a substance called imidazole propionate. This substance was found at higher levels in both the gut and the bloodstream of people with Parkinson’s disease. The scientists discovered that imidazole propionate can move through the body and reach the brain.
To better understand what this substance does, the team carried out experiments using mice. Some mice were given Streptococcus mutans directly in their gut, while others were given bacteria that were changed to produce the same enzyme. In both cases, levels of imidazole propionate increased in the blood and brain.
Over time, the mice began to show signs similar to Parkinson’s disease. They lost dopamine-producing brain cells, which are essential for controlling movement.
They also developed inflammation in the brain, movement difficulties, and a buildup of a protein called alpha-synuclein. This protein is known to collect in the brains of people with Parkinson’s and is believed to drive disease progression.
The researchers also discovered that these harmful effects depended on the activation of a specific cell signaling pathway known as mTORC1. When this pathway was blocked using a drug, the mice showed much less brain damage. Inflammation was reduced, fewer brain cells were lost, alpha-synuclein buildup decreased, and movement problems improved.
This finding is important because it suggests that the damage caused by oral bacteria is not random. Instead, it follows a clear biological pathway that could potentially be targeted with future treatments. By stopping the effects of harmful substances made by bacteria, it may be possible to slow or prevent brain damage.
At the end of the study, the researchers concluded that oral bacteria can influence brain health through the gut. This adds strong support to the idea that Parkinson’s disease may begin outside the brain, possibly years before symptoms appear.
When reviewing these findings, it is important to note that this research does not prove that poor dental hygiene directly causes Parkinson’s disease.
The study shows a strong biological link and explains how certain bacteria could increase risk, but more studies in humans are needed. However, the results strongly suggest that oral health, gut health, and brain health are deeply connected.
This research highlights the importance of good dental care, not just for teeth and gums, but possibly for long-term brain health as well. It also opens new directions for Parkinson’s research, including treatments that target gut bacteria or block harmful bacterial byproducts.
In the future, simple steps like improving oral hygiene or changing gut bacteria could become part of strategies to reduce the risk of Parkinson’s disease.
If you care about Parkinson’s disease, please read studies that Vitamin B may slow down cognitive decline, and Mediterranean diet could help lower risk of Parkinson’s.
For more health information, please see recent studies about how wheat gluten might be influencing our brain health, and Olive oil: a daily dose for better brain health.
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