A close-up of a male patient's head and face, with electrodes attached to the foreheadShare on Pinterest
The gut microbiome may hold the key to diagnosing Parkinson’s disease early. FG Trade/Getty Images
  • Parkinson’s disease affects the nervous system and causes uncontrollable movements, and can become debilitating over time.
  • Parkinson’s disease is incurable and often goes undiagnosed for years after symptoms begin, so researchers are looking for ways to diagnose it earlier and improve patient outcomes.
  • Chinese researchers recently conducted a study to see if there is any correlation between the gut microbiome and Parkinson’s disease.
  • The researchers found that people with REM sleep behavior disorder (RBD) had markers of Parkinson’s in their guts which may aid early diagnosis.

In a new study published in Nature Communications, researchers from The Chinese University of Hong Kong examined the link between Parkinson’s disease and the gut microbiome.

They did this by examining the gut microbiomes of four groups of participants, including one group with Parkinson’s disease and one group with REM sleep behavior disorder (RBD), as many people with RBD develop Parkinson’s.

The scientists found Parkinson’s disease markers in the guts of these RBD participants, which they believe can help with early diagnosis of the disease.

According to the National Library of Medicine (NLM), “The human microbiome is composed of bacteria, archaea, viruses, and eukaryotic microbes that reside in and on our bodies.”

These gut microbiota that exist in the human digestive tract help with digesting food, regulating neurotransmitters, and protecting against pathogens.

In recent years, research shows a connection between the gut microbiome and neurological conditions through the gut-brain axis.

The NLM describes the gut-brain axis as “the bidirectional communication between the central and the enteric nervous system, linking emotional and cognitive centers of the brain with peripheral intestinal functions.”

This connection highlights the importance of maintaining good gut health. Not only can good gut health help with digestion, but it can also improve neurological health.

Some ways to improve gut health include the following:

  • avoiding processed foods
  • eating a diet with whole foods
  • reducing stress
  • engaging in regular exercise.
  • eating fermented foods such as kombucha or sauerkraut (which are sources of probiotics)

The researchers used data from 441 participants in this cross-sectional study. They divided the participants into four groups.

The first group consisted of a control group (108 participants) with no prior history of RBD or Parkinson’s disease. The second group (170 participants) included people with an RBD diagnosis.

The third group (36 participants) had people with an early Parkinson’s disease diagnosis. The fourth group (127 participants) included first-degree relatives of people with RBD, which the authors called the RBD-FDR group.

The scientists analyzed the gut microbiota compositions of the participants’ stool samples. Additionally, they also used data collected from assessments that checked the severity of RBD symptoms, Parkinson’s disease traits, and gastrointestinal symptoms.

The researchers learned that the gut microbiota compositions in the early Parkinson’s disease and RBD groups contained markers that were not present in the control group.

The study identified 12 microbial markers that were present in the Parkinson’s disease and RBD groups. For example, the scientists found that the depletion of butyrate-producing bacteria was significant compared to the control group.

They also noted an “overabundance” of Collinsella and Desulfovibrio. Collinsella contributes to inflammation in the body.

These findings led the authors to believe that these markers can assist with the early detection of Parkinson’s disease. Since many people with RBD go on to develop Parkinson’s, this could help providers be on the lookout for Parkinson’s development and aid in diagnosis.

Another interesting finding in the study was that people in the RBD-FDR group saw increases in Collinsella and depletion of butyrate-producing bacteria compared to the control group. While their levels were not as high as people in the Parkinson’s or RBD group, this finding emphasizes the importance of monitoring the gut microbiome.

Dr. Daniel Truong, neurologist and medical director and founder of The Parkinson’s and Movement Disorder Institute at MemorialCare Orange Coast Medical Center, who was not involved in this study, spoke with Medical News Today and offered his thoughts about this research.

“In the case of Parkinson’s disease, alterations in the gut microbiome have been linked to increased inflammation, oxidative stress, and neuroinflammation, all of which are thought to contribute to the degeneration of dopaminergic neurons in the brain,” he said.

Dr. Truong also commented on the findings having the potential to lead to early detection of Parkinson’s disease.

“Early diagnosis allows for regular monitoring of the disease, which can help detect changes in symptoms and disease progression. This can help healthcare providers adjust treatment plans as needed and provide support and guidance,” he said.

Dr. Nadim Jafri, a gastroenterologist at Memorial Hermann in Houston, also not involved with this study, weighed in on the study for MNT.

“The molecular interaction between the gut microbiome and nervous system is complex. More and more studies are showing that an imbalance in the gut microbiome, known as dysbiosis, is associated with the onset and progression of neurological disorders,” said Dr. Jafri.

While Dr. Jafri called the research “highlights the importance of gut microbiota in neurologic conditions,” he noted a study weakness.

“The sample size was small and the study was limited to a small cohort in Hong Kong, it’s uncertain if these markers will be found or can be used in any meaningful way in other ethnicities around the world,” he said.

Getting adequate sleep is important on many levels. As the National Institutes of Health notes, it can improve both mental and physical health.

There are different phases and stages that occur during sleep, and one of the most important ones is Rapid Eye Movement (REM) sleep. REM sleep occurs periodically throughout sleep and accounts for 25% of the sleep cycle.

The REM part of sleep is considered especially important for cognitive health.

During REM sleep, the brain is highly active, and people experience vivid dreaming and go through memory consolidation.

According to the American Psychological Association, “During REM sleep, the brain busily replenishes neurotransmitters that organize neural networks essential for remembering, learning, performance and problem solving.”

As such, if someone does not get adequate REM sleep, this can contribute to cognitive deficits. Additionally, poor REM sleep causes issues with mood regulation and emotional procession, which can lead to anxiety and depression.

While sleep recommendations vary by age, the Centers for Disease Control and Prevention recommend a minimum of 7 hours of sleep per night for adults ages 18 to 60.