2020 Year-end Wrap Up:
Parkinson’s & the Gut by Martha Carlin
It has been six years since the first research was published showing a strong connection between the microbiome (gut bacteria) and Parkinson’s Disease (PD). Since that time more than 500 scientific research papers have been published, nearly 200 in 2020, expanding our understanding of the importance of the microbiome in PD. This has become one of the most promising and rapidly expanding areas of research.
This paper from the Journal of Neurogasteroenterology discusses promising areas of research and treatment for PD with respect to the gut via probiotics and fecal transplantation. Researchers from Harvard recently showed how gut bacteria could be eating your medicine and others have shown how gut bacteria may be eating your memories. Probiotics are a new and promising area in the treatment of Parkinson’s and one of our key areas of interest at The BioCollective and BiotiQuest. Historically, other areas of Parkinson’s research that may ultimately tie to gut bacteria are in autoimmune antibodies, metabolic dysregulation, and iron/sulphur metabolism.
A Few Interesting Gut-Brain Axis Papers
Recent studies highlight the initiation of Parkinson's disease (PD) in the gastrointestinal tract, decades before the manifestations in the central nervous system (CNS). This gut-brain axis of neurodegenerative diseases defines the critical role played by the unique microbial composition of the "second brain" formed by the enteric nervous system (ENS). Compromise in the enteric wall can result in the translocation of gut-microbiota along with their metabolites into the system that can affect the homeostatic machinery. The released metabolites can associate with protein substrates affecting several biological pathways. Among these, the bacterial endotoxin from Gram-negative bacteria, i.e., Lipopolysaccharide (LPS), has been implicated to play a definite role in progressive neurodegeneration. This particular research is exciting as it further confirms the data from The BioCollective, Parkinson’s microbiome research collaborations.
Research continues to support the connection between gut dysbiosis, inflammation and Parkinson’s Disease. This paper in the journal Nutrients was published just under the wire for 2020. The paper discusses the nutraceuticals butyrate and niacin as potential targets for addressing dysbiosis and intestinal permeability. I found this particularly interesting since John has been taking niacin for a couple of years now and started a butyrate supplement called ProButyrate recently.
This Lancet paper by John Cryan and Ted Dinan, the leading researchers in the Gut-Brain-Axis reviews the gut microbiome in neurological disorders, including ten key Parkinson’s human studies and suggests a need for more mechanistic studies.
This paper from researchers from the Enteric Neuroscience Program at the Mayo Clinic reviews research to date in the microbiome and Parkinson’s disease summarizing the potential role of gut microbiota and the pathophysiology of PD. This review covers how gut microbiota are influenced by environmental toxins, aging and host genetics and moves to the effects on gut-brain-axis, barrier dysfunction, and immune dysfunction.
A Few Interesting Parkinson’s Disease and Probiotics Papers
Bowel Irregularity and chronic constipation are symptoms that can persist and precede a diagnosis by ten or more years. I like this study which showed a short two-week course of probiotics improved in quality of life and bowel regularity metrics.
Research has shown that the agricultural chemical paraquat is correlated with increased risk of Parkinson’s disease. The Central Valley of Northern California, where nearly 50% of the US produce is grown is known as Parkinson’s Alley. I like this study which used two animal models and found that a probiotic strain can reduce oxidative stress caused by paraquat exposure in both models.
The neurotoxin 6-hydroxydopamine (6-OHDA) is a time tested animal model of PD and continues to constitute a valuable topical tool used chiefly in modeling Parkinson's disease in the rat. The model infuses 6-OHDA to create massive destruction of nigrostriatal dopaminergic neurons and is used to investigate motor and biochemical dysfunctions in Parkinson's disease. While there are newer models to address finer motor deficits, this model has long been used in PD research. This study used a multi-strain (L.acidophilus, B. bifidum, L. reuteri, L. fermentum) probiotic treatment in Wistar Rats and found that in the probiotic treated group the number of injured neurons following injection was significantly lower (p=.009).
Neuroprotective effects of probiotics bacteria on animal model of Parkinson’s disease induced by 6-hydroxydopamine: A behavioral, biochemical, and histological study, Journal of Immunoassay and Immunochemistry.
About 50% of people will Parkinson’s experience some form of cognitive impairment. While this particular research is focused on Alzheimer’s, this science review paper, Do the Bugs in your Gut Eat Your Memories, covers research on an oral pathogen, Porphyromonas gingivalis. Our research at The BioCollective in Parkinson’s microbiome samples is showing some potential connections with an related strain of Porphyromonas in the gut. Extra vigilance in oral hygiene may have positive impacts on your health in many aspects.
While much of the funded research in Parkinson’s disease continues to be focused on human genetics, a very small percentage of PD is associated with familial genetic predispositions. Expanding research to the microbiome offers much promise. This vital “organ” is malleable and can be changed more readily with diet, nutrition and lifestyle. Someday we may even be able to identify the early signs of Parkinson’s in the microbiome signature and turn people back from the path of disease. This is one of the goals of the work we are doing at The BioCollective in Parkinson’s research.
At The BioCollective, we have been fortunate to collaborate with some of the top Parkinson’s research scientists around the globe, including Dr. Filip Scheperjans, Dr. Sarkis Mazmanian, Dr. Malu Tansey, Dr, Robert Friedland, Dr. Daniel Paredes, Dr. Lorraine Draper, and Dr. Colin Hill.
Our goal since the founding of The BioCollective, in 2015, has been to accelerate the path of discovering the complex contributing factors by collecting fecal samples and gathering data that can be shared across the research institutions to foster collaborative research. We believe this will accelerate more personalized approaches to treatment for Parkinson's and ultimately cures.
I look forward to bringing you the latest scientific research connecting the gut and the brain in Parkinson’s in this Scientific Summary section of my blog.