Changes in Gut Bacteria May Cause Parkinson’s: Study

Research links disruptions in the microbiome to Parkinson's and implicates Desulfovibrio bacteria's metabolic processes

Changes in Gut Bacteria May Cause Parkinson’s: Study
(MP Art/Shutterstock)
George Citroner
A recent study reveals a potential connection between Parkinson's disease and the gut microbiome, suggesting that infection with a specific bacteria, known as Desulfovibrio, contributes to the development of the degenerative brain disorder.

Researchers at the University of Helsinki observed that the presence of these bacterial strains in Parkinson's patients could lead to the aggregation of alpha-synuclein, a protein closely associated with the disease.

To further investigate this association in humans, the researchers analyzed stool samples from 10 Parkinson's patients and 10 healthy individuals. The findings show that all Parkinson's patients had Desulfovibrio bacteria in their gut microbiome, establishing the link between these bacteria and the disease.

People with Parkinson's also exhibited higher levels of Desulfovibrio bacteria compared to those without the condition, with a noticeable correlation between bacterial concentration and the severity of the symptoms.

Gut May Be Where Parkinson's Disease Starts

"The cause of Parkinson’s disease has gone unknown despite attempts to identify it throughout the last two centuries,” Per Saris, professor of microbiology at the University of Helsinki and study co-author, said in a statement.
It’s estimated that individual genes cause only about 10 to 15 percent of Parkinson's cases.

“Our findings are significant," Saris said.

They suggest that certain strains of Desulfovibrio bacteria are highly likely to be a causative factor in Parkinson's. He also noted that environmental factors are the primary cause of the condition.

The study discovered that Desulfovibrio strains obtained from individuals without Parkinson's disease didn't induce alpha-synuclein aggregation to the same extent.

The current study builds on previous research by Saris and team, which initially identified a higher prevalence and abundance of Desulfovibrio strains in Parkinson's patients, particularly in those with more pronounced symptoms, compared to healthy individuals.

Desulfovibrio bacteria produce hydrogen sulfide as a result of their metabolic processes.

Hydrogen sulfide is a gas neurotransmitter and can play an important role in the development of Parkinson’s, Dr. Mary Kay Ross, a fellow of the American College of Emergency Physicians and founder of the Brain Health & Research Institute, told The Epoch Times.

“Hydrogen sulfide can also raise the iron content in the cytoplasm, which exacerbates that alpha-synuclein aggregation," Ross said.

The excessive presence of Lactobacillus, a probiotic, and the imbalance of various other bacteria also play a role in Parkinson's patients, Dr. Guy Schwartz, co-director of the Stony Brook Parkinson’s and Movement Disorders Center at Stony Brook Medicine, told The Epoch Times.

“That’s a deviation from the normal, healthy, non-Parkinson’s disease colonization of the colon,” Schwartz said.

Similar patterns are also seen in diseases such as autism and irritable bowel syndrome.

“That, we believe, is sort of the genesis of disease processes," he said.

Constipation, Parkinson’s, and the Gut

The abundant bacteria may produce harmful substances or hinder the growth of beneficial bacteria that may play a role in preventing Parkinson's disease, Schwartz said.
Constipation, an early symptom of the degenerative disorder, might be linked to this microbial imbalance.

“Intestinal motility is also decreased with the high levels of hydrogen sulfide, which leads to constipation, seen in Parkinson’s; increased inflammation; and enhanced central nervous system damage," Ross said.

Constipation exacerbates the problem.

"The fecal matter doesn’t flow at a normal rate, in a normal volume, and this causes backup, and this backup is into the small intestine, and bacteria don’t belong in the small intestines," Schwartz said.

This leads to colonies of bacteria from the colon accumulating in the small intestine.

“These have a deleterious effect. We call it small intestinal bacterial overgrowth, and it’s not unique to Parkinson’s disease. Gastroenterologists are well familiar with it, and they treat it with antibiotics," he said.

Treatments for Patients With Abnormal Microbiome

“My Parkinson’s patients seem to always have very abnormal microbiomes,” Ross said.
She noted that in her practice, she attends to many patients with Parkinson's disease, and as part of her assessment, she routinely examines their microbiome using the Thorne Gut Health Test. This comprehensive test looks at shotgun metagenomics sequencing, providing a detailed analysis of digestion-related factors.

“We have tried to treat these patients using a blend of prebiotic fibers to feed the desired bacteria and change the microbial environment, but the Parkinson’s patients have only gotten worse, and then better once we stopped the prebiotics,” Ross said.

There was concern regarding the possibility of bacteria metabolizing drugs such as dopamine, potentially exacerbating the symptoms, according to Ross.

However, she said she has achieved remarkable results by addressing diet, which can influence the microbiome; making lifestyle changes; and using a device called a Portable Neuromodulation Stimulator, or PoNS, in an “off-label” manner to deliver translingual neuromodulation.
The PoNS device, typically used in walking therapy for multiple sclerosis patients, has shown promising outcomes in Ross's Parkinson's patients.
“I have found that my Parkinson’s patients with severe gait abnormalities and tremors respond well,” Ross said. “With this multimodal approach, I can lessen their disease symptoms by about 50 to 70 percent.”

The Possible Role of the Gut-Brain Connection in Parkinson's

Studies have shed light on the intriguing link between the gut microbiome and Parkinson's disease, suggesting a potential role of the gut-brain axis in the development and progression of the condition.

The feeling of “butterflies” in our gut is linked to our nervous system, Ross explained, highlighting that this is a genuine phenomenon and an indicator of the functioning of the gut-brain axis.

“The gut-brain axis is a bidirectional communication system between the gastrointestinal tract, the gut, and the central nervous system—the brain,” she said.

“There is a great deal of emerging research that suggests that alterations in the microbiome or the gut-brain axis can impact neurodegenerative diseases through several different mechanisms.”

Understanding the influence of the gut-brain axis on neurodegenerative diseases opens up novel opportunities for therapeutic interventions. These approaches may involve dietary modifications, the use of probiotics, and fecal microbiota transplantation to target the microbiome.

“However, further research is needed to fully comprehend the intricate mechanisms involved and develop effective interventions,” Ross said.

George Citroner reports on health and medicine, covering topics that include cancer, infectious diseases, and neurodegenerative conditions. He was awarded the Media Orthopaedic Reporting Excellence (MORE) award in 2020 for a story on osteoporosis risk in men.