Study shows a subtle shift in gut bugs with Parkinson’s gene mutation

Sep 2, 2026

Researchers find fewer friendly microbes in patients carrying the GBA1 mutation

Written by Marisa Horak, MS | Aug. 26, 2026

• Parkinson's disease patients with GBA1 gene mutations tend to have distinct shifts in the gut microbiome, with fewer protective microbes and more inflammation-promoting bacteria.
• Mutation carriers exhibit reduced anti-inflammatory butyrate-producing bacteria alongside elevated levels of microbes linked to gut inflammation.
• Further validation studies are needed to better understand the gut-microbiota-brain axis and its impact on Parkinson's progression.

People with Parkinson’s disease who carry mutations in the GBA1 gene tend to have higher levels of inflammation-promoting gut bacteria and fewer protective microbes than patients without the mutation, according to a new study.

While the overall diversity of gut bacteria remained similar between both groups, researchers uncovered key differences in specific bacterial strains that could influence how the disease progresses.

“This study suggests a subtle shift toward a more pro-inflammatory gut microbial profile in [Parkinson’s patients carrying GBA1 mutations], characterized by fewer butyrate-producing and more pro-inflammatory bacteria,” researchers noted.

The study, “Pathogenic GBA1 Variants and their Interaction with the Gut-Microbiota-Brain Axis in Parkinson’s Disease,” was published in Movement Disorders.

Genetics and the gut microbiome

The causes of Parkinson’s disease are not fully understood, but genetics is thought to play a role in determining disease risk. Mutations in the GBA1 gene are a well-established risk factor for Parkinson’s, and they can also cause a separate disorder called Gaucher disease.

The human digestive tract is home to billions of bacteria and other microscopic organisms, collectively known as the gut microbiome. A growing body of evidence suggests that the gut microbiome is dysregulated in Parkinson’s disease and may play a role in its development. However, much about the microbiome and its role in Parkinson’s remains unclear.

In the study, a team of U.S. scientists sought to determine whether the microbiome is altered in people with Parkinson’s who carry a mutation in the GBA1 gene. To find out, they conducted detailed analyses of stool samples from 36 patients: 16 with a GBA1 mutation and 20 without known Parkinson’s risk mutations.

Analyses showed that the gut microbiome’s overall diversity and community composition were comparable in Parkinson’s patients with or without GBA1 mutations. However, the researchers noted “subtle but potentially biologically relevant … differences.”

Gut bacteria may send different biological signals in Parkinson’s disease

Sep 1, 2026

News Medical Life Sciences - The University of Oulu - Aug 26 2026

A new study from the University of Oulu suggests that gut bacteria may send different biological signals in Parkinson’s disease. The findings add to growing evidence that changes in the gut could be linked to Parkinson’s disease and may eventually help researchers identify new underlying mechanisms for the condition.

Rather than looking only at which bacteria are present in the gut, the researchers focused on the biological messages they send. Gut bacteria release extracellular vesicles, tiny particles that carry proteins and other molecules and can travel between cells, likely extending the microbial signaling beyond the gut.

The study, published in iScience, found that people with Parkinson’s disease had more of these vesicles in their stool samples than healthy individuals. The vesicles were also larger on average and carried a different mix of bacterial proteins, suggesting that microbial communication may be altered in the disease.

Microbiome research has traditionally focused on which bacteria are present and how their relative abundance changes. Our findings suggest that we should also ask what these bacteria are sending out into the body.”

Anatoliy Samoylenko, Senior Research Fellow at the University of Oulu and author of the study

The researchers analyzed faecal samples from 20 people with Parkinson’s disease and 19 healthy controls. They isolated extracellular vesicles produced by the gut microbiota and characterized them using nanoparticle tracking analysis, electron microscopy, 16S rRNA sequencing and mass spectrometry-based proteomics.

The analyses revealed differences between the Parkinson’s disease and control groups at several levels. Both the gut microbiota itself and the vesicles it produced showed distinct bacterial compositions. The vesicles from people with Parkinson’s disease also carried a different set of proteins.