A few years ago, we told you about a study funded by The Michael J. Fox Foundation (MJFF) that linked alterations in gut bacteria to Parkinson's disease (PD). MJFF has continued to support research in this field, and, just a few months ago, we provided an update on research linking alpha-synuclein in the gut to Parkinson's symptoms.
A recently published study has revealed differences in gut bacteria in those with Parkinson's disease based on their medications and geographic locations, adding to our growing knowledge on this connection.
The Gut-Brain Pathway
Thousands of bacteria live in the gut, and they help digest food, make vitamins and support immune function. Gut cells are connected to the brain through certain nerves and via this link, researchers believe changes in the gut could potentially effect changes in the brain. In fact, alpha-synuclein, the sticky protein that clumps in the brains of those with PD, also is present in the gut of people with PD. And, one of the earliest symptoms to emerge in many people with Parkinson's is constipation. A greater understanding of gut bacterial changes may shed light on new ways to diagnose Parkinson's and manage symptoms throughout the course of disease.
Changes in Gut Bacteria Are Linked to Parkinson's Medications and Geography
In a recent study, published in the journal Movement Disorders, researchers at the University of Alabama at Birmingham (UAB) evaluated a group of 227 individuals, including people with Parkinson's and healthy controls, from Seattle, New York and Atlanta. They found different numbers of bacteria in the gut in those with PD compared to healthy volunteers, which confirmed findings from previous studies. They also found that certain Parkinson's medications, as well as the participant's geographic location, affected the types of bacteria in the gut. Researchers postulate that the changes observed due to Parkinson's drugs might explain some of their side effects and that the differences associated with geographic location may be a result of varied environments, lifestyles and diets.
Environmental Factors Also Affect Parkinson's Gut Bacteria
An important function of gut bacteria is to rid the body of environmental toxins. This study found that the make up of bacteria responsible for removing these toxins was different in individuals with Parkinson's, suggesting that exposure to environmental toxins may alter gut bacteria in those with Parkinson's. Previous studies also have linked pesticides (an environmental toxin) to an increased risk of developing PD.
More to Learn about the Gut-Brain Connection in Parkinson's
The study of gut bacteria in Parkinson's is active but there is much to learn about this association. Researchers at UAB plan to conduct another study in people with and without Parkinson's to confirm the results of this study.
"The present findings lend support to the notion that the composition of [gut bacteria] may hold new information for assessing efficacy and toxicity of Parkinson's medications," said Haydeh Payami, PhD, professor at the UAB School of Medicine, in a press release. "Additional studies are needed to assess the effects of those drugs, with larger numbers of treated and untreated patients as well as individuals who do not have Parkinson's."