A new study indicates that tiny particles of polystyrene can promote the clumping of a protein involved in Parkinson’s.

Plastic waste is a growing problem, and as plastics break down the pieces can be problematic. A new study in Science Advances suggests that tiny plastic particles may be the latest environmental contributor to Parkinson’s disease (PD).

Microplastics are defined as particles smaller than 5 millimeters in diameter — for comparison, a grain of rice is 6 millimeters— and can also include nanoplastics (less than 1 micrometer). According to past research, it is common for blood samples to contain polystyrene nanoparticles, which come from pieces of foam packing materials, cups and cutlery. Research has also shown that unlike other kinds of plastic, polystyrene nanoparticles can enter the brain.

Parkinson’s disease is diagnosed when a protein, called alpha-synuclein, begins to clump in vulnerable neurons in the brain. The clumping ultimately affects dopamine, the neurotransmitter that gets progressively lost in PD, leading to early signs of the disease. This new study shows that polystyrene nanoparticles can interact with alpha-synuclein and promote its clumping in test tubes, in brain cells grown in a petri dish, and in mice.

About the Study & Results

Nanoplastic contaminants promote alpha-synuclein clumping.

Researchers mixed alpha-synuclein “seeds” with nanoplastics in test tubes to see if the presence of nanoplastics triggered the clumping of alpha-synuclein. After three days, they observed that, when combined with alpha-synuclein seeds, the nanoplastics promoted the acceleration of alpha-synuclein clumping formations.

Nanoplastic contaminants interact with alpha-synuclein at very specific regions of the protein.

Using computer modeling, the research team predicted a strong interaction between polystyrene nanoparticles and a region of alpha-synuclein. To validate this prediction, the team created a shortened version of alpha-synuclein that lacked the region the nanoparticles were predicted to interact with. Without that part of alpha-synuclein, the nanoparticles did not stick to the protein in lab experiments, indicating that the computer model was accurate.

Nanoplastic contaminants accelerate alpha synuclein clumping in neurons.

In mouse neurons grown in a petri dish, the researchers observed that nanoplastics were internalized into a specific compartment within the cell, called the lysosome, where alpha-synuclein tends to clump. They found that the nanoplastics accelerated the accumulation of pathogenic alpha-synuclein in these cells.

Nanoplastic contaminants accelerate alpha synuclein clumping in the mouse brain.

The researchers injected alpha-synuclein seeds and nanoplastics into the brains of live mice and found that about 20% of dopaminergic neurons — those thought to be crucial in the development of Parkinson’s — internalized both. Injecting the combination into mice led to an increase in alpha-synuclein clumps in dopaminergic neurons and an increase in alpha-synuclein pathology (as measured by molecular markers) compared to injecting the seeds alone. In 3 of 10 mice injected, nanoplastics alone led to alpha-synuclein pathology.

Traces of polystyrene can be found in human brain tissues. Finally, in brain tissue samples obtained from people with Lewy body dementia, a condition characterized by the presence of alpha-synuclein aggregates, the research team identified traces of polystyrene. This discovery suggests the potential presence of plastic nanoparticles in the human brain.

Highlights

•  Alpha-synuclein clumping was triggered and/or accelerated by nanoplastics in three different models — test tubes, brain cells grown in a petri dish and in mice brains.
• The interaction between polystyrene nanoparticles and alpha-synuclein occurs at a specific region in the alpha-synuclein protein.
• In brain tissue samples from people with Lewy body dementia, traces of polystyrene can be detected, suggesting that plastic nanoparticles may be present in human brains.

What does this mean?

Plastic waste may be contributing to Parkinson’s as an environmental factor. However, we do not yet know how such interactions might be happening in humans and whether the type of plastic might play a role.

What do these findings mean to the people with PD right now?

People are exposed to and consume microplastics every day, through breathing, eating foods and drinking liquids — whether they are packaged in plastic or not. Studies like this one are integral to disentangling how the effects of environmental toxicants contribute to the development of PD — we now know that polystyrene nanoparticles can make their way into the brain. Explore the environmental risk factors connected to Parkinson’s.

People who are concerned that they may be experiencing Parkinson’s symptoms should talk to a healthcare provider.

Learn More

The Parkinson’s Foundation believes in empowering the Parkinson’s community through education. Learn more about PD and the topics in this article through our below resources, or by calling our free Helpline at 1-800-4PD-INFO (1-800-473-4636) for answers to your Parkinson’s questions.

• Environmental Factors
• PD & Pollution: Something in the Air
• Top Parkinson’s Science News Articles of 2023

“I study the brain’s immune cells, called microglia,” said Lindsay Mitchell De Biase, PhD, from the University of California, Los Angeles. “Any population of neurons, including dopamine neurons, are intimately surrounded by and permeated by these cells. Whenever there is a challenge to the central nervous system, whether that is an injury or an infection, these cells change the way they function and interact with neurons.”

Through her 2021 Parkinson’s Foundation Stanley Fahn Junior Faculty Award, Dr. De Biase is studying how microglia influence vulnerability of dopamine neurons to Parkinson’s disease (PD). She and her research team hope to find ways to harness the transformative nature of microglia to preserve dopamine neurons and slow PD progression.

Microglial cells regulate central nervous system inflammation and the signaling connections between neurons. Emerging research suggests that mitochondria, organelles which generate the energy necessary to power cells, play an important role in regulating how microglia function. Understanding this interaction between mitochondria and microglial function, particularly the ability of these cells to influence the health of dopamine neurons, is where Dr. De Biase’s research comes into play.

“Many gene mutations that increase the risk for Parkinson’s are mutations in genes related to mitochondrial function,” said Dr. De Biase. “We think that some of these mutations are increasing disease risk, not only by affecting energy production within neurons, but by pushing microglial cells into a damaging, inflammatory state.”

Dr. De Biase is using novel technology to study the role of microglial mitochondria in a mouse model of PD. The intervention strategy she developed could be used in people who are at high risk for developing Parkinson’s, to delay disease development or prevent it. In people with PD, the strategy could create a more neuroprotective environment and preserve remaining dopamine neurons to delay PD progression.

Dr. De Biase’s research involves manipulating the function of microglia to see if it can protect midbrain dopamine neurons, which regulate movement, and play an important role in PD progression. Microglia play a key role in promoting neuronal health by mitigating overactivity and assisting in the formation of new connections between neurons. Dr. De Biase is working to harness these beneficial actions, seeking to “program” microglia to protect dopamine neurons and slow PD progression.

“Microglia are dynamic, malleable cells and could represent therapeutic targets that are highly distinct from others that have been explored thus far,” said Dr. De Biase.

“My greatest hope from our work comes from the fact that microglial cells are so dynamic,” she said. “These cells really can change their properties in many different contexts, and I think that makes them one of the most targetable cell populations in the brain. So, my hope is that what we are learning will reveal strategies that are really feasible for harnessing the neuroprotective abilities of these cells.”

Meet more Parkinson’s researchers! Explore our My PD Stories featuring PD researchers.

To solve a puzzle, you need all the pieces. Right now, Parkinson’s disease (PD) researchers are working to identify all the pieces in the brain and how they fit together to form Parkinson’s. Every year, scientists get closer to gathering all the pieces, understanding how this disease works in order to solve it.

Our Science News blog series focuses on the latest Parkinson’s studies and how they can impact you or your loved one living with this disease. 2023 was a busy year for PD research. Explore the top Science News articles of 2023:

1.  Artificial Intelligence Study Detects Parkinson’s from Breathing Patterns

Parkinson’s is not always easy to diagnose or monitor. Unfortunately, there is no single test — besides a doctor assessing symptoms — to diagnose Parkinson’s or predict the course of the disease.

Prior studies have shown a connection between Parkinson’s and breathing patterns. Using this data, researchers created a new AI system that uses breathing patterns while a person is sleeping to help diagnose and monitor disease progression — with 90% accuracy.

READ THE FULL ARTICLE

2.  Blood Test Can Help Track PD Symptoms and Progression

Diagnosing and treating Parkinson’s early on can lead to better disease management and a higher quality of life. This study found evidence of molecular changes in the blood that mirror changes in the brain of people with Parkinson’s who experience cognitive and movement symptoms.

Understanding and identifying these molecular changes is essential for developing new minimally invasive tests that would not only diagnose Parkinson’s but help track its progression and how it responds to treatment.  To connect these dots, this study looked at RNA (a molecule essential for various biological processes) for answers.

 READ THE FULL ARTICLE

3.  Study Finds Promise in Treatment for PD-Related Constipation

Constipation impacts more than 60% of people with Parkinson’s. Of those with PD who suffer from constipation, it is often chronic, severe and unresponsive to standard treatments. A new drug is hoping to change that.

In Parkinson’s, the protein called alpha-synuclein clumps in the brain. These clumps can also form in the nerves of the gastrointestinal (GI) tract, which can decrease the strength and coordination of the bowels, resulting in constipation. In a clinical trial, the biotech company Enterin tested ENT-01, a compound designed to act on nerve cells in the GI tract and prevent this protein from clumping. This drug was found to help people with Parkinson’s who experience constipation.

READ THE FULL ARTICLE

4.  Test Could Detect Parkinson’s Before Symptoms Appear

By the time a doctor makes a PD diagnosis, the disease has most likely progressed for years before early signs even show. However, this study adds promising new data to support a test that may allow Parkinson’s to be diagnosed before symptoms appear.

In the brains of people with Parkinson’s, the protein alpha-synuclein clumps. There are different types of clumping, including a type that act as “seeds” that spread, much like a red sock in the washing machine can turn everything pink. When these misfolded proteins clump together, they eventually kill brain cells, and PD symptoms appear. This study used a test called an alpha-synuclein seed amplification assay (SAA) that distinguishes between people who do or do not have Parkinson’s. The study found that SAA detected early Parkinson’s 87% of the time.

READ THE FULL ARTICLE

5.  The Link Between Inflammation & Early Parkinson’s

Inflammation plays a key role in helping the immune system recognize and fight illness and disease. However, if inflammation persists over long periods of time — which might be the case in Parkinson’s — it can begin to do more harm than good. New research suggests that inflammation may play a critical role when it comes to predicting and treating Parkinson’s.

In this study, researchers sought to determine whether inflammation is present early in Parkinson’s, and whether certain markers of inflammation were connected to particular symptoms.

READ THE FULL ARTICLE

6.  PD in the Feces: Stool Samples Could Detect Early PD

From constipation to medication absorption and nutrition, the gut plays a role in Parkinson’s. This is why a team of researchers set out to design a study that links a stool sample test to a PD diagnosis.

To develop a test for a disease, researchers often rely on a biological indicator (called a biomarker). The alpha-synuclein protein is a potential biomarker of Parkinson’s, and when it clumps, it can be detected in the saliva, tears, urine and blood of people with Parkinson’s. However, there is no test that can reliably predict or diagnose Parkinson’s using these samples. This new investigated how alpha-synuclein levels detected in stool samples could predict Parkinson’s.

READ THE FULL ARTICLE

Ready to participate in Parkinson’s research? Visit ourJoin A Study page to learn more.

In a word, momentum was the theme for the Parkinson’s Foundation in 2023. Thanks to the Parkinson’s community, especially our donors, we worked hard to make life better for people with Parkinson’s disease (PD) through advancing research and prioritizing access to care.

Here are 11 ways you helped us keep the momentum in 2023: 

1. Addressed Critical Gaps in Access to PD Care

In July 2023, we published a study that found that only 50% of people with Parkinson’s saw a general neurologist. As a result of these findings, we are expanding disease-specific training to neurologists and other healthcare providers, and pursuing ways to improve access to care across all demographic and population groups.

Learn more

2. Provided Genetic Testing and Counseling to 11,000 people with PD

In 2023, our global genetics study PD GENEration: Mapping The Future of Parkinson’s Disease reached the milestone of providing genetic testing and counseling to 11,000 people with Parkinson’s. PD GENEration test results empower people, help them work alongside their doctor to tailor PD treatment, and can match them to gene-specific clinical trials. Thus far, PD GENEration data shows that 12.7% of people with Parkinson’s have a genetic link to the disease — much higher than the originally believed 5-10%.

Enroll Now

3. Designated 8 New Care Centers to Further Access to Care

To bring specialized Parkinson’s care to more people, we designate medical centers that know how to treat this complicated disease. In 2023, we designated eight new centers as part of our Global Care Network, with the first-ever designations in Wisconsin and Washington, and the country of Japan.

View all centers in the Global Care Network

4. Continued Investment in Parkinson’s Virtual Biotech

The Parkinson’s Virtual Biotech, a partnership with the Parkinson’s UK, is currently funding 13 potential medications in development that either address PD symptoms or aim to slow, stop, or prevent the disease altogether. This initiative gets us closer to delivering life-changing treatments in years, not decades.

Learn more

5. Funded 30 Researchers through Grants

A Parkinson’s breakthrough can happen at any time, in any lab, which is why we directly fund scientists who are conducting innovative studies attacking Parkinson’s from every angle. In 2023, we awarded $2.8 million across 30 promising research grants.

Explore our ongoing research

6. Partnered with first historically Black institution of medicine to become a PD GENEration research site

Ensuring diversity and inclusivity in Parkinson’s research is critical to accelerating breakthroughs toward a cure. In 2023, we partnered with Morehouse Healthcare to expand genetic research in the Black community, making Morehouse the first historically Black institution of medicine to become a PD GENEration research site.

Read now

7. Funded Local Parkinson’s Programs in 35 States

We awarded nearly $1 million in community grants to PD programs across 35 states. From non-contact boxing classes to educational events and wellness programs, we have invested more than $10.4 million in 787 community-based programs since 2011.

Visit your local chapter’s webpage to find a program near you
You can also call our Helpline at 1-800-4PD-INFO (1-800-473-4636).

8.  Launched New Accredited Courses for Community Healthcare Professionals

Even though 90,000 Americans are diagnosed with Parkinson’s every year, most healthcare professionals — including nurses, pharmacists and general practitioners — do not receive in-depth PD care training. We added new accredited online courses to our Education Series for Community Providers, which are designed to improve treatment and outcomes for people with Parkinson’s.

Explore Parkinson’s training tools designed for professionals

9. Launched 50 New Spanish Webpages

We launched 50 new Spanish pages on Parkinson.org. From symptoms to managing PD, these pages are designed to reach the Spanish-speaking Parkinson’s community and connect them to key information and tools.

Explore our Spanish pages

10.  Raised $3.5 million through Parkinson’s Champions

Parkinson’s Champions are a dedicated group of people in the PD community who fundraise to help us fight Parkinson’s. Parkinson’s Champions do it all, they run in prestigious races, cycle for Parkinson’s Revolution, host Facebook fundraisers, and more. In 2023, Parkinson’s Champions raised $3.5 million to propel us towards a cure.

On April 11, the producing team behind the Broadway hit, A Beautiful Noise: The Neil Diamond Musical presented $500,000 to the Parkinson’s Foundation in honor of legendary singer, songwriter and performer Neil Diamond, who is living with Parkinson’s.

Learn more about Parkinson’s ChampionS and create your own fundraiser

11.  Presented Research and Care Findings at International Conferences

Every year, the top neurologists and Parkinson’s experts in the world attend renowned conferences to share new information about PD treatments and research. In 2023, the Parkinson’s Foundation shared numerous research and care findings at two premier conferences.

Read our 6 findings shared at the International Congress of Parkinson’s Disease and Movement Disorders®

Read our 11 findings shared at the Sixth World Parkinson Congress

As much as we accomplished in 2023, we are committed to doing more for the PD community in 2024. Your continued support is the only way we can make that happen. Thank you.

According to a new study, data from smart devices may be able to detect Parkinson’s disease years before a diagnosis.

What if a smartwatch could detect Parkinson’s disease (PD) before you knew something was wrong? A new study in Nature Medicine used digital movement sensors, the kind of technology found in smart devices, to detect Parkinson’s disease years before a clinical diagnosis.

By the time a person is diagnosed with Parkinson’s, they have already lost 50% to 70% of dopamine neurons. Their brain cells involved in memory, movement, motivation, mood and attention have degenerated. Due to this reality, researchers are eager to find accurate, affordable and non-invasive tools to help detect Parkinson’s sooner.

The Methods

For this study, researchers used smart devices with a movement tracker to collect information on participants’ movement and activity levels. The study assessed years of data points to find patterns that point to Parkinson’s. Researchers utilized data from a randomly selected group of 103,712 people participating in the UK Biobank, a study of more than 500,000 people aged 40–69 years with ongoing follow-up of clinical status. They used a wrist-worn accelerometer, which can detect movement and rate of speed changes (acceleration), to study average acceleration for each hour of the day, as well as sleep patterns, over a seven-day period.

The Results

Reduction in acceleration can be seen before PD diagnosis. Over the course of two years, 273 participants were diagnosed with Parkinson’s. Another 196 people received a new PD diagnosis more than two years after they collected the data. Remarkably, in the 196 people who received a PD diagnosis after the study, researchers saw a reduction in their average daytime acceleration several years before their PD diagnosis, during what is known as the prodromal stage (where early signs are present but no clinical diagnosis has been made).

No other diagnosis shows a similar pattern. Parkinson’s disease was the only diagnosis associated with a reduction in movement before (the prodromal stage) and after diagnosis. This reduction did not correlate with other diagnoses, including Alzheimer’s, dystonia (a sustained or repetitive muscle twisting, spasm or cramp) or osteoarthritis.

Sleep disturbances are more marked in PD than in other disorders. Using the movement data, researchers found reduced quality and duration of sleep both before and after PD diagnosis compared to people without PD. People diagnosed with PD slept fewer hours overall, had fewer consecutive hours of sleep and slept more frequently during the day than both people without PD and those in the prodromal stage. Sleep deterioration was observed in other diagnoses, but not to the same extent as seen in PD.

Acceleration data predicts prodromal PD. To test whether prodromal PD could be predicted based on the data, researchers created a model using age, sex and average acceleration. They successfully identified cases of Parkinson’s before diagnosis from the UK Biobank population. This model was better at predicting PD than a model that relied on other PD markers, including genetics, lifestyle (such as smoking or heavy alcohol use) and blood biomarkers.

Acceleration data predicts time to diagnosis. Finally, researchers leveraged the data to build a model to accurately predict the amount of time until a PD diagnosis. They also found that their model could predict the probability of not receiving a Parkinson’s diagnosis in the following several years.

While several studies have shown that changes in movement (including the use of digital gait measures) can be associated with prodromal PD, this is the first study to show the potential usefulness of accelerometers in detecting PD years before a clinical diagnosis.

Highlights

• Wrist-worn movement trackers could detect changes in average acceleration years before a PD diagnosis, during the prodromal stage.
• Only participants with PD experienced a reduction in acceleration both before and following a diagnosis, suggesting this measure is disease-specific and can potentially be used in early identification for people likely to be diagnosed with PD.
• The accelerometry model could predict who would develop PD, and when the diagnosis might be expected.

What does this mean?

This study shows that the reduction in acceleration is PD-specific and can be detected years before a clinical PD diagnosis. This may mean that in the future, doctors may be able to leverage activity data from a smart device to diagnose Parkinson’s disease earlier.

However, more studies are needed before smart device data become a widely available diagnostic tool. Overall, more research is needed to help clinicians detect and confirm an early Parkinson’s diagnosis.

What do these findings mean to the people with PD right now?

People who are concerned that they may be experiencing Parkinson’s symptoms should talk to a healthcare provider.

Learn More

The Parkinson’s Foundation believes in empowering the Parkinson’s community through education. Learn more about PD and the topics in this article through our below resources, or by calling our free Helpline at 1-800-4PD-INFO (1-800-473-4636) for answers to your Parkinson’s questions.

• 10 Early Signs
• Walking with Parkinson’s: Freezing, Balance and Falls
• Science News: A New Test Could Detect Parkinson’s Before Symptoms Appear
• Science News: Sleep and Parkinson’s: Non-Motor Quality of Life

The brain and gastrointestinal (GI) system are connected. Resident bacteria, including that in the gut, are unique to every person and a major part of our makeup — bacteria even outnumber cells in the body. The capability of that bacteria, known as the microbiome, is enormous. New research strongly suggests a link between the gut and Parkinson’s disease (PD). Learn what science is finding and discover how you can begin improving gut health today.

This article is based on Parkinson's and the Gut-Brain Connection a Parkinson’s Foundation Expert Briefing webinar presented by Carley Rusch, PhD, RDN, LDN, Medical Science Liaison at Abbott Nutrition.

The Gut’s Microbiome

The gut microbiome spans from the mouth to the colon. It is the network of microorganisms — bacteria, viruses, fungi and more — and their collective genetic material that lives within the intestinal tract. The greatest density and diversity of these microorganisms are found within the colon.

Studies on the relationship between gut bacteria and health date back hundreds of years. Research on the benefits of bacteria in yogurt for treating diarrhea was recorded as early as the 1400s. Today, technology known as high-throughput DNA sequencing gives researchers the power to rapidly identify the thousands of bacterial DNA present in individual stool samples.

Science is uncovering the many ways the gut microbiome can influence brain health, body function and overall wellbeing. It can even impact how the body processes oral medications.

Exploring the Gut-Brain Relationship in PD

Research suggests that what happens in the gut influences the brain by way of the gut-brain axis — a biochemical communication between the gastrointestinal tract and the central nervous system.

While research on Parkinson's and the microbiome is in its infancy, scientists have found the gut bacteria in people living with PD differs from that of people without PD.

In Parkinson's, alpha-synuclein proteins misfold and form clumps in the brain. These clusters are called Lewy bodies. It has been suggested that these clumps, which are also found in other neurodegenerative diseases, may trigger the loss of dopaminergic neurons. As scientists have dug deeper into Parkinson’s progression, they have also been able to find alpha-synuclein pathology along the GI tract in people with Parkinson's.

What Science Can Tell Us

Gastrointestinal dysfunctions are some of the most common and troublesome non-movement symptoms in PD. Constipation affects up to 70% of people with Parkinson's and often begins before the onset of PD’s telltale movement symptoms and other early signs.  It's estimated that up to 75% of people with Parkinson's will also experience speech and swallowing issues. Gastroparesis, delayed emptying of the stomach, is another common PD symptom.

Knowing that alpha-synuclein pathology can also be found along the GI tract in Parkinson’s, over the years researchers have genetically sequenced the microbiome of different people with Parkinson's. They found that some beneficial bacteria, such as Prevotella, Faecalibacterium and Roseburia, are reduced in people with Parkinson's, when compared to someone without the disease. However, researchers also found a boost in other bacteria, such as Bifidobacterium and Lactobacillus, in people with PD — possibly due to constipation.

Research also shows zonulin, a protein marker of intestinal absorbency, found in inflammatory GI conditions such as celiac disease, inflammatory bowel disorders (IBD), diabetes and other autoimmune diseases, is also significantly elevated in people with Parkinson’s. This increased intestinal permeability potentially leads to what is referred to as “leaky gut” (a decrease in the intestinal barrier that can set off inflammation and disease).

Diversity Matters

A healthy microbiome is a diverse one. Research shows decreased microbial diversity in people with inflammatory bowel disorders, such as ulcerative colitis and Crohn's disease, compared to the resident gut bacteria in healthy people.

Diseases, including Parkinson's and IBD, diet and lifestyle all impact gut bacteria diversity. What we eat, how often we exercise, where we live and stage of life all play a role. Other influences include stress, antibiotic and pharmaceutical drug use and pollutants.

Researchers theorize that these factors influence the production of signaling metabolites, which determine whether the gut makes beneficial, anti-inflammatory or inflammatory molecules, such as those that impact cholesterol metabolism, cardiovascular and brain health and more. Communication among signaling metabolites can influence the GI tract, immune system, the liver, brain, lungs, skeletal muscle and other areas of the body.

While various factors can impact on gut microbiota, generally, the microbiome is very stable. Antibiotic or probiotic use often shows short-term changes in resident microbiota, but over time — as a person discontinues use of such medication or supplements and reverts into a familiar diet — the resident microbial makeup typically returns to where it was.

Taking Charge Through Diet

One of the best strategies to improve gut health is increasing fiber. While a probiotic may only introduce one bacteria strain, a fiber-fueled diet can be broken down by multiple types of gut bacteria to encourage a new microbial community to take up residence in the gut, benefitting GI and heart health, improving immune function and easing constipation.

When gut bacteria break down fiber it naturally produces health-boosting short chain fatty acids. These acids boost the gut’s mucus barrier to fight inflammation, protect brain and heart function and more.

Research shows a high-fiber, whole food, plant-fueled diet, with high consumption of fruits and vegetables (known as a Mediterranean-style diet) can increase butyrate and other beneficial bacteria. Right now, researchers are interested in butyrate, a fatty acid that is a major energy source for creating healthy new gut bacteria and can influence immune function.

Plant-Rich, Fiber-Driven Meals Matter

A Mediterranean-style diet is associated with lower risks of developing Parkinson’s, higher microbial diversity and improved heart and cognitive health. Studies also show incorporating this whole-food based diet, along with healthy fats, such as extra virgin olive, oil, nuts and seeds can ease PD symptoms.

To boost gut health experts recommend:

• Eating at least 14 grams of fiber for every 1,000 calories — about 28 grams for someone eating 2,000 calories a day. The average American only consumes half of the recommended daily fiber.
• Filling half your plate with vegetables and fruit.
• Eating prebiotic fibers such as bananas, onions, garlic, chicory root, artichokes, beans, grapes and cranberries.

For some people with Parkinson’s, taking certain PD medications with a protein-rich meal — like meat, fish, eggs, dairy products, nuts and beans — may interfere with absorption, slowing medication effectiveness. Talk to your doctor about whether a protein-redistribution diet, a popular solution for motor fluctuations, might be right for you. This means eating most of your daily protein during your last meal of the day.

On the Horizon

The research on dietary interventions to alter gut microbiota is entering a new era. Scientists are currently exploring:

• Probiotics: benefits specific to probiotic species and strain. Healthcare experts use the Clinical Guide to Probiotic Products Available in USA to inform research-based recommendations. There is no recommended consumption of probiotics in PD but bring up this topic with your doctor.
• Postbiotics: “a preparation of inanimate microorganisms and/or their components that confers a health benefit on the host,” according to the International Scientific Association for Probiotics and Prebiotics (ISAPP). Studies show potential for using postbiotics to ease symptoms of irritable bowel syndrome, treat infections and more.
• Synbiotics: prebiotics combined with probiotics, defined by ISAPP as “a mixture comprising live microorganisms and substrate(s) selectively utilized by host microorganisms that confers a health benefit on the host.” These are being investigated to potentially improve PD symptoms and more.

Researchers are also investigating how machine learning and artificial intelligence might aid in modifying gut bacteria. Entering information from an individual’s stool sample, diet, genetics and other medical data into a machine-learning model could identify precision nutrition to modify a person’s microbiome.

Learn More

Explore our resources about the gut-brain connection in Parkinson’s:

• Podcast: The Role of the Microbiome in PD
• Blog: How an Innovative Research Center Studies the Gut–Brain Connection
• Science News: Stool Samples Could Detect Early Parkinson’s
• Library: Nutrition and PD