Aug 24, 2026
Benefits appeared to involve mechanisms beyond preserving dopamine function
Written by Patricia Inácio, PhD | Aug. 18, 2026
- More physical activity was linked to slower decline in certain motor and cognitive measures and caudate DAT availability.
- Greater activity was tied to slower worsening of rigidity, axial symptoms, overall motor severity, and processing speed.
- Clinical benefits were not explained by DAT preservation, suggesting other brain mechanisms may be involved.
Higher levels of physical activity are associated with slower worsening of certain motor symptoms and better preservation of certain measures of cognitive function in people with Parkinson’s disease, according to a recent study.
People who were more physically active also showed a slower decline in dopamine transporter (DAT) availability in the caudate, a brain region affected by Parkinson’s. But that preservation of dopamine function did not explain the slower motor and cognitive decline linked to greater activity, suggesting other brain mechanisms may contribute to the benefits.
The study, “Physical activity promotes clinical benefits beyond dopaminergic preservation in Parkinson’s disease: a longitudinal analysis of the PPMI cohort,” was published in Neurological Research and Practice.
Physical activity may influence Parkinson’s progression
Parkinson’s disease is caused by the progressive loss of dopamine-producing nerve cells. Dopamine is a chemical messenger that helps the brain control movement, and its loss contributes to characteristic Parkinson’s motor symptoms such as rigidity, slowed movement, tremor, and walking difficulties.
Cognitive and other nonmotor symptoms also are common and can involve brain pathways beyond the dopamine system.
One way researchers can track changes in the dopamine system is by measuring DAT availability. DAT is a specialized protein on nerve cells that clears dopamine after its release into the space between nerve cells. In Parkinson’s, there is a steady decrease of the transporter in the brain, reflecting the progressive loss of dopamine-producing neurons.
Physical activity has consistently been associated with better outcomes in Parkinson’s, including slower worsening of gait and postural problems, daily functioning, and processing speed. But researchers still do not know exactly why activity may help, including whether its benefits come from protecting dopamine-producing nerve cells.
To find out, researchers in South Korea examined data from the Parkinson’s Progression Markers Initiative (PPMI), an ongoing observational study that follows people with newly diagnosed Parkinson’s who show reduced DAT availability on brain scans.
Participants had at least four years between physical activity assessments and at least two evaluations of DAT availability, motor symptoms, and cognitive function. The researchers analyzed DAT imaging, motor function, and cognitive function separately, using the available data for each. DAT availability was measured in the caudate and putamen, two major parts of the striatum, a brain region affected by Parkinson’s.
Physical activity was assessed using a questionnaire in which participants reported the intensity, frequency, and duration of their leisure, household, and work-related activities during the previous week. Researchers averaged participants’ scores over follow-up to estimate their usual level of physical activity.
The results showed that higher physical activity levels were significantly associated with a slower decline in DAT availability in the caudate, but not in the putamen.
Aug 21, 2026
August 11, 2026 - National Institutes of Health
At a Glance
- Researchers identified a drug candidate that enhanced effectiveness and reduced side effects of the standard Parkinson’s disease treatment in animal models.
- If the drug candidate proves effective in people, it could be an effective way to improve treatment for Parkinson’s disease.
The brain needs a precise balance of chemicals to work correctly. Even small shifts in that balance can cause problems. This makes it challenging to develop treatments for brain disorders without causing side effects.
The standard treatment for Parkinson’s disease involves such a trade-off. Parkinson’s disease occurs when brain cells that produce the chemical dopamine die. This leads to movement problems such as shaking, stiffness, and difficulty with balance.
A medication called levodopa helps patients by increasing dopamine levels in the brain. However, it can also cause rapid, involuntary twisting or writhing movements. This side effect is called dyskinesia. Levodopa also becomes less effective the longer patients take it.
An NIH-funded research team led by Dr. Aarash Bordbar at Sinopia Biosciences looked into how levodopa reduces Parkinson’s symptoms and causes dyskinesia. They used that knowledge to find a drug candidate that could boost levodopa’s benefits and reduce its side effects. The results were published in Science Translational Medicine on July 15, 2026.
Prior research in a mouse model of Parkinson’s disease showed levodopa changes gene activity in brain cells that respond to dopamine. The team linked some of those changes to levodopa’s beneficial effects and others to dyskinesia.
The researchers then looked for a drug candidate with the same effects on genes linked to levodopa’s benefits, but the opposite effects on genes linked to dyskinesia. Their search of a database of existing candidates turned up a chemical compound called SB-0107.
They tested combinations of SB-0107 and levodopa in rodent models of Parkinson’s disease. The team looked at how the treatment affected movement and gene activity in a brain region containing cells that respond to dopamine. SB-0107 had similar effects as levodopa on genes linked to levodopa’s benefits. It also boosted levodopa’s beneficial effects on movement symptoms. Additionally, SB-0107 countered levodopa’s effects on genes linked to dyskinesia and avoided inducing or exacerbating dyskinesia in rats.
Aug 20, 2026
Study findings could help guide new treatment approaches
Written by Margarida Maia, PhD | Aug. 18, 2026
- Parkinson's disease is linked to specific alterations in gut bacterial communities that differ from healthy individuals.
- These microbial variations are closely associated with patient age, disease severity, and medications.
- Further research is needed to determine if gut microbiome changes directly drive symptom progression.
Changes in gut bacteria may be linked to Parkinson’s disease and can vary with age, disease severity, and medications, but more research is needed to understand whether these changes actually contribute to how symptoms develop and progress, a study suggests.
“These findings regarding the relationships between microbial communities and disease characteristics warrant further investigation and may inform the development of novel therapeutic approaches for managing Parkinson’s disease,” researchers wrote.
The study, “Gut microbial dysbiosis in a Southern Chinese cohort of patients with Parkinson’s disease,” was published in Antonie van Leeuwenhoek.
Several bacterial groups more common in patients than in controls
There is increasing evidence that bacteria and other microbes living in the digestive tract, called the gut microbiome, may play a role in how Parkinson’s develops and progresses. Changes in the normal balance and variety of the gut microbiome may affect the communication between the gut and the brain via the gut-brain axis.
“However, bacterial profiles can vary based on factors like diet, age, and medication use,” the researchers wrote.
To understand whether and how the gut bacteria differ in Parkinson’s when considering factors like age, disease severity, and medication usage, the researchers compared stool samples collected from 42 patients and 25 age-matched control individuals. A technique called 16S rRNA gene sequencing was used to identify and compare the bacteria in the samples. The 16S rRNA gene is a piece of genetic material that can distinguish different bacteria.
Of the 42 patients, 18 were men and 24 were women. Their mean age was 64.1 years. Most patients were taking dopamine agonists (85.7%) or levodopa (83.3%). Dopamine agonists work by mimicking dopamine, the brain chemical that is missing in Parkinson’s, while levodopa provides the body with a precursor it can convert into dopamine.
Aug 19, 2026
Study found a dose-response pattern, with the highest odds within 500 feet
Written by Margarida Maia, PhD | Aug. 11, 2026
- Living near dry cleaners was associated with higher Parkinson’s odds in adults age 67 and older.
- The association was strongest among those living within about 500 feet, but the study did not establish that long-term TCE exposure caused the higher odds.
- The researchers said more study is needed to better understand environmental exposures and the regional differences seen in Parkinson’s risk.
People age 67 and older who lived closer to dry cleaners had higher odds of Parkinson’s disease than those who lived farther away, according to a U.S. study. The researchers said exposure to dry-cleaning chemicals such as trichloroethylene (TCE) could help explain the association, but more research is needed.
The highest odds were among those living within 500 feet of a dry cleaner, with particularly strong links in the Dallas–Fort Worth area, parts of the South, the Detroit area, and the New York City metropolitan area extending into New Jersey.
Dry-cleaning chemicals may contribute to Parkinson’s risk
“Our findings suggest that chemicals used in dry cleaning may contaminate nearby neighborhoods and contribute to [Parkinson’s] risk,” the researchers wrote in “Nationwide association between proximity to dry cleaners and risk of Parkinson’s disease,” published in npj Parkinson’s Disease.
Breathing certain chemicals may fuel the buildup of protein clumps called Lewy bodies in the brain. Lewy bodies can damage nerve cells and lead to symptoms of Parkinson’s. One chemical, TCE, a solvent used in dry cleaning, can persist in soil, air, and groundwater for many years and has been linked to an increased risk of Parkinson’s. The researchers noted, however, that they could not specifically test measured TCE levels in relation to Parkinson’s risk in this study.
This study examined whether living near dry cleaners was associated with Parkinson’s. It included U.S. Medicare beneficiaries age 67 and older who lived within five miles of a dry cleaner. The researchers compared 180,982 people newly diagnosed with Parkinson’s with more than 18.8 million people who did not have the disease.
Parkinson’s was more common in older adults and men — patterns already well known from previous research. However, the closer people lived to a dry cleaner, the higher their odds of Parkinson’s. Those living within 500 feet of a dry cleaner had 14% higher odds than those living four to five miles away.
The strongest link was found for Parkinson’s with gait disturbance or postural instability, which can cause problems with walking and maintaining balance. People living within about 500 feet of a dry cleaner had 23% higher odds of Parkinson’s with these gait problems than those living four to five miles away.
Aug 18, 2026
In trial, treatment showed benefits in those with early-onset disease
Written by Margarida Maia, PhD | Aug. 10, 2026
- The U.S. Food and Drug Administration has awarded fast track status to an experimental stem cell therapy for Parkinson's disease.
- XS411 is a ready-to-use therapy designed to replace lost dopamine-producing nerve cells and restore neurological function in patients.
- The treatment candidate is now being tested for early Parkinson's in a clinical trial in China.
An off-the-shelf, or ready to use, stem cell therapy that’s designed to replace the nerve cells lost in Parkinson’s disease and restore neurological function has been put on a developmental fast track by the U.S. Food and Drug Administration (FDA).
The FDA awarded fast track status — a designation that could mean a faster pathway through regulatory review if clinical data are positive — to XS411, being developed by China-based Xellsmart. Clinical trials have already been cleared in both China and the U.S. to test the injection therapy.
According to the developer, a Phase 1/2 study (NCT07166757) in China has shown benefits with the therapy’s use in people with early-onset Parkinson’s.
In a company press release, Xellsmart called the new U.S. designation a “key milestone for [the] global clinical development” of XS411. Such status offers more frequent communication with the FDA and access to rolling review, which means parts of the data can be submitted as they become available rather than waiting until the full package is ready before filing for approval.
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