Groundbreaking Trial Finds That Infrared Light Therapy for Parkinson’s Disease Reduces Symptoms and Improves the Gut Microbiome
Ron Till, 69, was exhausted. Two years previously he had lost the ability to have a good night’s sleep. He would go to bed early, only to be awoken by his body jerking violently, one of his many symptoms of Parkinson’s disease.
But things changed for the better when he signed up for a novel clinical trial assessing the effectiveness of infrared light therapy for Parkinson’s sufferers.
“It improved my sleep so much,” Mr Till, who lives in Mannum, South Australia, said. Within weeks of commencing the trial, which involved applying infrared light therapy to his head and abdomen, three times a week, for 12 weeks, he stopped jerking awake. “I got back my two blocks of four hour sleep, which is like gold to me,” Mr Till said.
Mr Till was so pleased with his improvement that once the study ended he purchased a light helmet device used in the trial and continues to use it for twenty minutes every second day. “Sometimes I forget to bring it when I go to visit my brother in Robe,” Mr Till said. “And my sleep goes downhill fast.”
Mr Till credits his ongoing use of light therapy for preventing his Parkinson’s symptoms from getting worse. “I would recommend this therapy to other people with Parkinson’s,” he said. “Since I started the light treatment I’ve plateaued so nicely that my neurologist has reduced my three monthly visits to yearly.”
The results of the trial, which involved 19 participants in NSW and SA, showed that Till was not an isolated case, with most participants demonstrating improvements in Parkinson’s symptoms and signs including gait, balance, cognition and fine motor skills after receiving infrared light therapy.
In addition, the trial examined for, and found, changes in the participants’ gut microbiome, which meant that this was the first known trial worldwide to demonstrate changes in the human gut microbiome following infrared light therapy.
Dr Brian Bicknell, microbiologist and lecturer at the Australian Catholic University, says he came up with the idea following a brainstorming session with his colleagues in 2016 to discuss why a monkey previously involved in an experiment on Parkinson’s disease, would show improvement in symptoms after receiving infrared light therapy only to its abdomen.
“I suggested it was probably the microbiome,” Bicknell said. “The gut microbiome seems to be incredibly important to our own overall health.”
The Australian study’s microbiome findings, which are being published in The Journal of Photochemistry & Photobiology, B: Biology, offer a potential ray of hope for the approximately 80 000 Australians and 10 million people worldwide who are facing a long, slow decline from a progressive neurodegenerative disease for which treatment options are limited. This number of Parkinson’s sufferers is only expected to increase in the future with the world’s ageing population and, chillingly, the recently hypothesised link between contracting COVID-19 and an increased risk of Parkinson’s disease.
The number of cells in the gut microbiome, which is comprised of all the bacteria, protozoa and fungi that colonise the gastrointestinal tract (GIT), is estimated to be a hundred trillion, which is as many as the number of cells in the rest of our entire body.
There has been increased interest in the gut microbiome over recent years, with dysbiosis (an unbalanced microbiome) being linked to a number of medical disorders, including neurodegenerative disease, cardiovascular disease, asthma, diabetes, irritable bowel syndrome (IBS), inflammatory bowel disease (IBD), colorectal cancer and obesity.
There has long been a postulated link between Parkinson’s disease, the gastrointestinal tract and the gut microbiome. The gut microbiome in Parkinson’s patients has been shown to be altered compared to those of the general population. Constipation affects 90 per cent of Parkinson’s sufferers, often preceding the initial diagnosis by many years. And there is an increased risk of Parkinson’s disease in those who already have IBS or IBD.
The reason for this link is undetermined, however the prime suspect is a protein known as alpha-synuclein. Abnormal accumulations of this protein in nerve cells form microscopically visible lesions known as Lewy bodies which are associated with a decreased ability to repair the DNA damage and increased cell death.
Lewy bodies have been detected in the GIT up to 20 years before the diagnosis of Parkinson’s disease. They are also present in high numbers in the brain of Parkinson’s patients, especially in the basal ganglia.
It is hypothesised that inflammation leads to increased alpha synuclein accumulation in the GIT, with some of this excess being transported to the brain via the vagus nerve. This hypothesis is supported by the fact that those who have undergone a surgical transection of the vagus nerve are less likely to develop Parkinson’s disease.
Improvements in the gut microbiome may reduce GIT inflammation and permeability, thereby reducing alpha-synuclein transportation to the brain, as well as increasing beneficial microbial metabolic byproducts such as serotonin, GABA and dopamine, thereby reducing the risk of Parkinson’s disease and improving symptoms in those who already have the disease.
There is even recent epidemiological evidence that antibiotic usage may increase the risk of developing Parkinson’s disease, by altering the gut microbiome.
In a retrospective study, published in the journal Movement Disorders last year, researchers from the Department of Neurology at the Helsinki University Hospital, compared oral antibiotic usage in Parkinson’s disease patients with randomly selected controls. Soberingly a statistically significant increased risk of Parkinson’s disease was found in those who had taken antianaerobic or tetracycline antibiotics 10-15 years before, antifungals 1-10 years before, and/or trimethoprim or sulphonamide antibiotics 1-5 years before their initial diagnosis with Parkinson’s disease.
Australasian Research Institute’s Dr Ann Liebert and her colleagues had already found, through earlier research, that the gut microbiome of mice could be altered through administration of infrared light therapy. They wished to see if this finding could be replicated in humans.
Nineteen volunteers with Parkinson’s disease from NSW and SA were recruited. All participants were between the ages of 60 – 80 and had mild to moderate symptoms and signs of Parkinson’s.
The participants gave a faecal sample to researchers before the trial began, and were asked not to alter their dietary habits or day-to-day activities during the duration of the study. The participants were then given infrared light therapy via laser devices to their abdomen at a wavelength of 904-nanometres, and to their head at a wavelength of 810-nanometres and/or their neck at a wavelength of 904-nanometres, three times a week for twelve weeks.
At the end of the 12 weeks a further faecal sample was collected from each participant, and the microbiome from each of these faecal samples were subsequently analysed via DNA extraction and testing.
“It was incredibly exciting to see changes in the microbiome and improvements in symptoms happening at the same time,” Liebert said. “Even more excited when we saw the same kind of changes in the Sydney trial where we treated the abdomen only.”
The majority of participants showed a significant increase (defined as at least a log2-fold change) in 10 different genera of microorganisms including Bacteroides, Alistipes and Prevotella and a significant decrease in 17 different genera including Bifidobacterium, Streptococcus and various Clostridium and Enterococcaceae genera.
Interestingly two of the bacterium that showed an increase – Bacteroides and Prevotella – have been shown in multiple studies to be reduced in the gut microbiome of Parkinson’s sufferers. In fact low levels of Prevotella is so strongly associated with a more rapid progression and greater severity of Parkinson’s that it has been proposed as a biomarker for the disease. And Bacteroides is considered beneficial to the microbiome through its anti-inflammatory properties and production of healthy short chain fatty acids.
Five of the bacteria that showed a decrease post light therapy – Bifidobacterium, Streptococcus, Lactobacillus, Christensenella and Enterococcaceae – have been shown in multiple studies to be increased in the microbiome of Parkinson’s sufferers.
Several of the bacteria are generally considered detrimental to the microbiome. Enterobacteriaceae is thought to decrease gut integrity and produce pro-inflammatory metabolites; Clostridium genera are associated with high fat diets and Type 2 diabetes; and Streptococcus is considered to be potentially pathogenic.
“It is quite possible that laser will provide a synergistic effect to the currently available therapeutic manoeuvres [to the gut microbiome]”, Professor of Cardiology at Macquarie University, Hosen Kiat, said. “It is a no-brainer if it is useful because it is relatively cheap, it is non-invasive and it has zero side effects.”
Not all the microbiome findings, however, were as expected. Both Lactobacillus and Bifidobacterium are considered to be beneficial to the microbiome, yet both bacteria showed a significant decrease in the majority of participants following light therapy.
“We know that very few diseases have a magic bullet treatment,” Kiat said. “I don’t want to overall any technology in its infancy. But if I were a Parkinson’s patient I would seek out the laser and I would use the same protocol as we described.”
Despite these uncertainties, one of the trial’s participants, Margaret Jarrett, 75, is convinced of light therapy’s benefits. As an avid flower gardener at her home in Adelaide she was dismayed when she developed anosmia (loss of smell) as a result of her Parkinson’s disease.
After several weeks of therapy, however, she regained her sense of smell. “It’s amazing, you go outside and I suddenly smell the perfume of murraya in full bloom,” Mrs Jarrett said.
Mrs Jarrett noted another improvement post therapy. For years she had been plagued with debilitating irritable bowel syndrome. “I never knew what the morning would be like,” Mrs Jarrett said. “I like to get up early and go for a walk and sometimes I would get caught short.”
Interestingly, two bacteria that have been found to be elevated in IBS, Dorea and Enterococcaceae, were found to be decreased post light therapy in Liebert’s trial.
“The laser has really helped me not to have diarrhoea,” Mrs Jarrett, who continues to administer light therapy via a hand-held device to her abdomen three times a week, said.
David Harrison, 62, from Sydney, is another trial participant. Diagnosed with Parkinson’s disease in his mid-50s, Mr Harrison’s symptoms had become so severe that he was having to use his left hand for most tasks. “Eight weeks after starting laser therapy I was driving myself home and I suddenly realised I was right-handed again,” Mr Harrison said. “I couldn’t believe it!”
Post-trial Mr Harrison purchased a hand-held laser device and also continues to use it three times a week. “I still take my medications for Parkinson’s, I think it’s prudent to do that,” he said. “But I use the light therapy as well. I’m doing everything I can to beat Parkinson’s.”
It is impossible at this stage to know whether the improvements in the trial participants’ Parkinson’s symptoms were due to the effect of infrared light therapy to the brain, or due to changes in the gut microbiome, or partially due to a placebo effect, or, most likely, a combination of the above. What is unquestioned however is that exposure to light therapy did alter the gut microbiome, seemingly for the better, and that further research in this area is urgently needed.
What is also apparent is the gratitude of the trial participants for being introduced to light therapy.
With his Parkinson’s symptoms in check, Mr Till plans to do more travelling. “I have family up on the Gold Coast. And I think to myself, ‘Can I drive that far?’ Before it was impossible but now I think, ‘Perhaps I can’.”
As for Mrs Jarrett, she has some important advice for others who may be diagnosed with Parkinson’s disease. “Don’t despair and don’t panic,” she said. “Be open-minded about adjunctive therapies and get a good team to support you. When I was first diagnosed with Parkinson’s I said to my doctor, ‘It’s not going to get me. I’m going out to meet it’.”
- The non-abridged version of this article was first published in The Weekend Australian on May 29, 2021.
Suvi Mahonen is a Surfers Paradise-based journalist. Her work appears in The Australian, the Australian Quarterly, Mamamia and other health and lifestyle publications. Follow her on Facebook, YouTube and online art-selling platform Redbubble.