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.