It was previously inferred that the debilitating neurological disease may be caused by outside factors. According to the “dual hit” hypothesis, an unknown pathogen may enter the human body through the nose or the gastrointestinal tract. The pathogen is then believed to stimulate certain pathological processes that trigger the onset of the disease.
As part of the recent study, a team of researchers at the University of Luxembourg, the University Medical Center Goettingen and University Marburg in Germany examined samples from the nose and gut of 76 patients with Parkinson’s disease and 78 healthy controls.
The health experts also examined the microbiome of 21 participants with idiopathic rapid-eye-movement sleep behavior disorder (iRBD). It was believed that people with this sleep disorder were at an increased risk of developing Parkinson’s disease later in life.
The results showed that the bacterial communities in the intestines significantly varied between the three groups. The scientists also observed that the majority of the differential bacteria had similar trends in those who had iRBD. Certain intestinal bacteria were also tied to non-Parkinson’s symptoms such as depression.
However, the research team did not observe significant differences in bacterial composition in the participants’ nasal cavities.
“We hope that, by comparing the groups, we will learn to better understand the role of the microbiome in the process of the disease and to find out what changes occur and when. This might deliver new starting points for early treatment of the disease. It would also be essential knowledge for one day being able to use the absence or presence of certain bacteria as a biomarker for early detection of the disease,” lead researcher Professor Paul Wilmes told Science Daily online.
Recent findings coincide with previous study
The results of the recent study were reflective of a research published early this year.
Just this March, a team of researchers at the University of Alabama at Birmingham have demonstrated a link between gut microbiome and Parkinson’s disease onset.
As part of the study, the health experts examined 197 patients with Parkinson’s disease and 130 healthy controls from various metropolitan areas across the U.S. including Seattle, New York, and Atlanta.
According to the researchers, patients with the disease exhibited an imbalance in their intestinal bacteria. Experts said some species of gut bacteria were present in large volumes in Parkinson’s patients compared with their healthier counterparts. Certain medications were also observed to affect the composition of gut microbiome. (Related: Cholesterol-lowering drugs may accelerate onset of Parkinson’s disease, according to researchers.)
Researcher Haydeh Payami said it could mean that certain drugs alter the gut microbiome composition in some people, which in turn may cause additional health problems as a manifestation of unwanted side effects. Payami also stressed that the growing pharmacogenomic industry may need to take intestinal bacterial communities in making tailored disease treatments.
“This opens up new horizons, a totally new frontier. There are implications here for both research and treatment of Parkinson’s disease. Therapies that regulate the imbalance in the microbiome may prove to be helpful in treating or preventing the disease before it affects neurologic function…The present findings lend support to the notion that the composition of the gut microbiome may hold new information for assessing efficacy and toxicity of Parkinson’s medications. 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,” Payami said in another Science Daily article.