Listen to your Gut: Maintaining Your Gut Health Can Reduce Your Risk For Parkinson’s Disease

By Cameron Manard

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In life, there are so many difficult decisions and so many stressful events that we have to deal with. When it comes to food, we just want to eat something that makes us happy. In the moment, we can’t understand why something that tastes so good could be bad for us. Our first thoughts might just be how much weight we might gain from it or how expensive it is. It’s rare to think that how we eat could affect our brains.

Parkinson’s Disease (PD) is a neurodegenerative disease with symptoms affecting both motor and non-motor functions (3). Non-motor functions, such as constipation and depression, generally appear years before diagnosis. By the time of diagnosis, motor symptoms such as tremors and bradykinesia (the slowing of movements) have developed (3, 2). As PD progresses, the symptoms continue to worsen and individuals with PD have greater chances of developing forms of psychosis and dyskinesia. What is frightening is that this debilitating disease has only seen an increase in the amount of patients diagnosed.

In PD, there are certain factors such as the environment the individual is living in and the genetics that they have that increase their risk of developing it. Certain genes, such as PRKN and SNCA, have been associated with PD (1). It has also been shown that about 15 percent of individuals diagnosed with PD have a degree of family history connected to the disease. Even though genetic factors can create an inherent risk for PD, environmental factors are almost certainly needed for its development (4). These factors include head trauma as well as ingesting certain toxins such as herbicides, pesticides, metals, and air pollution. The head trauma makes sense because we know that the brain is very fragile. What might be confusing, however, is how ingesting toxins could lead to a neurodegenerative disease.

Understanding that begins with what is known as the microbiome-gut-brain axis. In our gastrointestinal tract, we have our enteric nervous system (ENS) which contains hundreds of millions of neurons (6). Each one of these neurons has its own function to assist in digestion. Our microbiome is able to use the ENS to communicate with the central nervous system (CNS) through our vagus nerve (5). Most of the time, this axis works to regulate the body and keep both systems in homeostasis. In the case of PD, however, they lead to a vicious cycle.

In their study, Pan-Montojo et al. found that this same gut-brain axis could be the cause of why consuming toxins could lead to the development of PD (9). In their study, they gave rotenone, a dangerous pesticide known to increase the risk of PD, to mice in doses low enough to not be present in the brain or brainstem immediately. They found that when the pesticide was only given to the ENS, it caused an increase in the amount of α-synuclein, the protein commonly connected to PD. They also found that the mice that consumed the low amount of rotenone developed symptoms of PD in a matter of months.

Due to studies such as this, new research has been focused on learning more about how the gut microbiomes of individuals with PD compared to those that don’t. A meta-analysis conducted by Shen et al. found that individuals with PD show similar deviations in which families of microbiota are more or less abundant in their gut (10). They also hypothesized that these same deviations could be what is causing some of the conditions associated with PD. Another study conducted by Mertsalmi et al. found evidence that constipation experienced by individuals with PD has connections with a reduction of one of Prevotella, a specific bacteria in the gut (8).

Toxins aren’t the only thing that is harming your microbiome though. Our microbiome feeds on dietary fiber, something that is severely lacking in our westernized diet (7). The westernized diet (WD) is one that full of processed foods such as burgers, fries, and sodas. Foods made with refined ingredients and little to no fruits or vegetables. The WD is not only giving us many other conditions such as obesity and autoimmune diseases but it is also starving and killing the good bacteria in our microbiome. Without a full and healthy microbiome, our risk of developing PD increases (11).

But, no matter where you are in life, there is still time to improve your diet. The Mediterranean diet is one of the best for improving your microbiome (7). It is filled with foods such as legumes and fruit that are high in fiber. These foods saturate the good bacteria in our microbiome. It has been found that the more one follows the Mediterranean diet, the less their risk of developing PD (11).

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That being said, change is difficult, and it can take time. It is difficult to switch out of a diet that we have become accustomed to. What is important is to continue taking steps towards improving your microbiome, no matter how little they might be. Each fruit you eat, each time you have water with your meal instead of soda, each time you take a second to think about what you are putting in your body and you hesitate just a little bit more, you are moving towards the path of improving your chances at a healthy life that much more. So next time you are stressed and hungry, think about how the food is not only affecting your body but your brain as well. Your future self will thank you for it.

Works Cited

1. Bandres-Ciga, S., Diez-Fairen, M., Kim, J. J., & Singleton, A. B. (2020). Genetics of parkinson’s disease: An introspection of its journey towards Precision Medicine. Neurobiology of Disease, 137, 104782. https://doi.org/10.1016/j.nbd.2020.104782
2. Berardelli, A., Rothwell, J. C., Thompson, P. D., & Hallett, M. (2001). Pathophysiology of Bradykinesia in parkinson’s disease. Brain, 124(11), 2131–2146. https://doi.org/10.1093/brain/124.11.2131
3. Bloem, B. R., Okun, M. S., & Klein, C. (2021). Parkinson’s disease. The Lancet, 397(10291), 2284–2303. https://doi.org/10.1016/s0140-6736(21)00218-x
4. De Miranda, B. R., Goldman, S. M., Miller, G. W., Greenamyre, J. T., & Dorsey, E. R. (2022). Preventing parkinson’s disease: An environmental agenda. Journal of Parkinson’s Disease, 12(1), 45–68. https://doi.org/10.3233/jpd-212922
5. Elfil, M., Kamel, S., Kandil, M., Koo, B. B., & Schaefer, S. M. (2020). Implications of the gut microbiome in parkinson’s disease. Movement Disorders, 35(6), 921–933. https://doi.org/10.1002/mds.28004
6. Fleming, M. A., Ehsan, L., Moore, S. R., & Levin, D. E. (2020). The enteric nervous system and its emerging role as a therapeutic target. Gastroenterology Research and Practice, 2020, 1–13. https://doi.org/10.1155/2020/8024171
7. García-Montero, C., Fraile-Martínez, O., Gómez-Lahoz, A. M., Pekarek, L., Castellanos, A. J., Noguerales-Fraguas, F., Coca, S., Guijarro, L. G., García-Honduvilla, N., Asúnsolo, A., Sanchez-Trujillo, L., Lahera, G., Bujan, J., Monserrat, J., Álvarez-Mon, M., Álvarez-Mon, M. A., & Ortega, M. A. (2021). Nutritional components in western diet versus Mediterranean diet at the gut microbiota–immune system interplay. implications for health and disease. Nutrients, 13(2), 699. https://doi.org/10.3390/nu13020699
8. Mertsalmi, T. H., Aho, V. T., Pereira, P. A., Paulin, L., Pekkonen, E., Auvinen, P., & Scheperjans, F. (2017). More than constipation — bowel symptoms in parkinson’s disease and their connection to gut microbiota. European Journal of Neurology, 24(11), 1375–1383. https://doi.org/10.1111/ene.13398
9. Pan-Montojo, F., Anichtchik, O., Dening, Y., Knells, L., Pursche, S., Jung, R., Gille, G., Spillantini, M. G., Reichmann, H., & Funk, R. (2009). Progression of parkinson’s disease pathology is reproduced by intragastric administration of rotenone in mice. Nature Precedings. https://doi.org/10.1038/npre.2009.3352.1
10. Shen, T., Yue, Y., He, T., Huang, C., Qu, B., Lv, W., & Lai, H.-Y. (2021). The association between the gut microbiota and parkinson’s disease, a meta-analysis. Frontiers in Aging Neuroscience, 13. https://doi.org/10.3389/fnagi.2021.636545
11. Wang, Q., Luo, Y., Ray Chaudhuri, K., Reynolds, R., Tan, E.-K., & Pettersson, S. (2021). The role of gut dysbiosis in parkinson’s disease: Mechanistic insights and therapeutic options. Brain, 144(9), 2571–2593. https://doi.org/10.1093/brain/awab156

Pictures Works Cited

1. Uzunovic, A. (2021). Brain Model on Plate [Photograph]. Pexels. https://www.pexels.com/photo/brain-model-on-plate-15410078/
2. Olsson, E. (2018). Flat-lay Photography of Vegetable Salad on Plate [Photograph]. Pexels. https://www.pexels.com/photo/flat-lay-photography-of-vegetable-salad-on-plate-1640777/