Can Our Microbiome Treat Parkinson’s?

Written: June 2022

Nearly one million people in the U.S. are living with Parkinson’s disease. This represents more than the combined number of people diagnosed with multiple sclerosis, muscular dystrophy, and Lou Gehrig’s disease, and the number is growing. Parkinson’s is a long-term degenerative disorder of the central nervous system which mainly affects the motor system. The most obvious early symptoms are tremor, rigidity, slowness of movement, and difficulty with walking. There is no known cure.

Some people with Parkinson’s who do not respond well to medications are treated with deep brain stimulation. A doctor implants electrodes into part of the brain and connects them to a small electrical device implanted in the chest. The electrodes stimulate specific areas in the brain to help stop movement-related symptoms of Parkinson’s such as slowness of movement and tremor.

Elon Musk’s company called Neuralink may also play a role. Its technology includes a chip-sized device embedded in the brain and connected to several wires smaller than a strand of human hair. The wires are strategically placed within the brain. The device can be controlled by software. The Neuralink technology is not a short-term solution for Parkinson’s but at a minimum the company hopes the neural interface may facilitate study of the disease and ultimately treat severe neurological conditions.

The primary therapy for Parkinson’s is levodopa, also called L-dopa. Levodopa can control symptoms of slow movements and stiff, rigid body parts. Brain cells change the levodopa into dopamine. Dopamine is a type of neurotransmitter, sometimes called a chemical messenger. Your body makes it, and your nervous system uses it to send messages between nerve cells. Dopamine plays many roles including how we feel pleasure and how we think and plan. Too much or too little dopamine can lead to a range of health issues including Parkinson’s disease.

Researchers at the University of Georgia have engineered probiotic bacteria which can synthesize L-dopa. Preclinical tests in animals have shown the new treatment approach is not only safe and well-tolerated but also can eliminate side effects which eventually develop with traditional L-dopa therapy. The probiotic bacteria the researchers used are live microorganisms from our gut.

Within the human body, we have 10 times more microorganisms living in our gut than human cells. Some scientists consider humans to be superorganisms. One scientist used the analogy we are “the Mothership with a lot of passengers on board”. There is much we don’t know about these microorganisms, but a lot of research is underway, including projects to sequence the genomes living in our guts. The University of Georgia research project is taking advantage of the potential to create new methods of drug delivery using what lives inside of us.