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Parkinson's disease

Parkinson’s disease is the second most common neurodegenerative disease in France. It progressively destroys the dopamine neurons in the brain. A link to a disruption in intestinal microbiota has been shown.

Parkinson’s disease affects 1% of people over 65 in France, which represents about 100,000 people. The substantia nigra in the brain, the area that controls movement, loses the neurons that produce dopamine. The result is progressive motor symptoms: slowness in movements, muscle rigidity, and tremors. People who have Parkinson’s also face non-motor problems, like sleep problems, depressive episodes, and incapacitating gastrointestinal problems (constipation, bloating, abdominal pain, nausea).

Age is implicated

The primary risk factor is obviously age. Although genetic predispositions have been proven, no single one is sufficient to explain the disease. Environment is also a factor, with pesticides playing a documented role.

Gut-brain communication

Intestinal microbiota participates in communication between the intestine and the brain. Some researchers have hypothesized that chronic intestinal infection by Helicobacter pylori could be the origin of Parkinson’s disease. However, it hasn’t been determined whether the infection triggers the disease or, on the contrary, the disease promotes the infection.
Dysbiosis, meaning a fault in the composition of microbiota, has been highlighted in patients with Parkinson’s disease. They have fewer “anti-inflammatory” bacteria and more “pro-inflammatory” bacteria than healthy people.

Controlling progression and testing

Treatment focuses on limiting the motor symptoms of the disease (tremors, rigidity, etc.) through the use of dopamine precursors. These treatments don’t prevent the progression of the disease, and complications reappear after 5 to 10 years of treatment. Currently, the primary goal is to detect the disease as early as possible and slow down neural degeneration. Manipulating microbiota is one option currently being studied. 


Dossier Inserm
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