"Parkinson’s attacks the mind, body, and the spirit. There is one thing that treats all three, and that’s hope."

 - Gordon Adai

Parkinson’s disease (PD) is one of the most common neurodegenerative diseases in our world today. Studies have shown that one out of every 100 people over the age of 60 develops PD, and increased average life span will result in a greater proportion of the population suffering from the disease [1].

Symptoms of Parkinson’s

Many signs of Parkinson’s disease are commonly recognized and visible to other people. These include tremors, slowed movement, muscle rigidity, and posture and balance impairments. Other symptoms, such as constipation and anxiety, are less evident to others and can actually begin occurring a decade before other PD symptoms.

Physiological Signs

Closely related to Parkinson’s is the hormone dopamine. Dopamine helps coordinate neuromotor function. As we age, neurons that produce the hormone can begin to die, and movement then becomes impaired. Decreased dopamine levels cause limb and facial tremors, as well as rigidity that leads to abnormal gait. Cognitive and behavioral problems may also appear.

Another sign of the disease is Lewy bodies. Found in the brain of patients, these clumps of neural protein interfere with a range of neural functions, including memory, movement, thinking, mood, and behavior. Traces of the protein that makes up Lewy bodies have been found in the gut of those with PD, and animal studies [2] have shown that once the molecule accumulates in digestive tracts, it can travel via the vagus nerve directly into the brain, causing symptoms seen in Parkinson’s.

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Lewy Bodies are clumps of neural proteins that can accumulate in our cells

Altered Gut Microbiome

A study published in 2017 comparing 197 Parkinson’s patients and 130 healthy individuals from around the US discovered the gut flora of these two groups differed significantly in both the type of microbe species and their proportions [3]. This suggests that an imbalance in gut microbes is a possible risk factor for PD, and that regulating intestinal flora might be one way to treat or even prevent the disease.


Considering Parkinson’s connection to dopamine and the gut together with PS128’s ability to modulate dopamine concentration [4], a group of Taiwanese scientists designed a study to determine whether the psychobiotic strain could have a positive effect on the symptoms of PD [5].

Study on Mice with PD-like Symptoms

Research Methods

In the experiment, one group of mice were injected with MPTP, a molecule that destroys dopaminergic neurons, mimicking the necrosis of these cells as seen in Parkinson’s and consequently inducing PD symptoms. One portion of these MPTP mice was fed PS128 daily and a second was given a saline placebo. Another cohort was not given MPTP but received only PS128, while a final control group was given only saline. The experiment lasted 28 days.


Research confirmed that treatment with PS128 resulted in dopaminergic neuron protection, effectively preventing the pathophysiological damage like that seen in Parkinson’s. The psychobiotic enhanced the mice’s physical activity and coordination and ameliorated their movement and balance disorders.


Dopamine neural cells were protected.


Dopaminergic neurons congregate in the brain’s substantia nigra region. When they die, dopamine levels in the brain decrease, triggering PD symptoms such as tremors or loss of balance. In order to identify a change in the number of dopaminergic neurons in the substantia nigra of mice that had developed Parkinson’s-like symptoms, researchers visually observed the amount of tyrosine hydroxylase, a dopamine-synthesizing enzyme, which had been marked with fluorescent dye.


In the mice exposed to MPTP with only saline treatment, significantly fewer dopaminergic neurons remained, in contrast to relatively high numbers of neurons in those that were treated with PS128. The psychobiotic was shown to effectively protect neuron cells responsible for dopamine production.



Movement speed and control increased.

In experimental mice, MPTP induces PD-like symptoms such as slow movement and balance impairment. During the pole-climbing experiment, test mice climbed from the top down to the bottom of a pole. Their activity level and speed were recorded, with normal mice taking less than 10 seconds to complete the task. The MPTP mice with only saline treatment climbed down sluggishly, their limbs uncoordinated, taking around 40 seconds to reach the bottom, while their PS128-treated counterparts took on average only 15 seconds. The test showed that PS128 can improve mobility and grip strength, reversing MPTP-induced sluggishness.


Balance improved.

Normal mice can cross a narrow beam 100 cm long in under 10 seconds. During the experiment, the MPTP-saline cohort walked unsteadily, their limbs weak and tails unable to assist in maintaining balance. As a result, they spent more than 30 seconds crossing the beam. On the other hand, the MPTP mice that received PS128 moved with ease, tails lifted high, crossing steadily in less than 20 seconds. PS128 has the potential to improve movement and balance disorders.

[1] Tysnes, O. B., & Storstein, A. (2017). Epidemiology of Parkinson's disease. Journal of neural transmission (Vienna, Austria : 1996), 124(8), 901–905.

[2] Kim, S., Kwon, S. H., Kam, T. I., Panicker, N., Karuppagounder, S. S., Lee, S., Lee, J. H., Kim, W. R., Kook, M., Foss, C. A., Shen, C., Lee, H., Kulkarni, S., Pasricha, P. J., Lee, G., Pomper, M. G., Dawson, V. L., Dawson, T. M., & Ko, H. S. (2019). Transneuronal Propagation of Pathologic α-Synuclein from the Gut to the Brain Models Parkinson's Disease. Neuron, 103(4), 627–641.e7.

[3] Hill-Burns, E. M., Debelius, J. W., Morton, J. T., Wissemann, W. T., Lewis, M. R., Wallen, Z. D., Peddada, S. D., Factor, S. A., Molho, E., Zabetian, C. P., Knight, R., & Payami, H. (2017). Parkinson's disease and Parkinson's disease medications have distinct signatures of the gut microbiome. Movement disorders : official journal of the Movement Disorder Society, 32(5), 739–749.

[4] Liu, Y. W., Liu, W. H., Wu, C. C., Juan, Y. C., Wu, Y. C., Tsai, H. P., Wang, S., & Tsai, Y. C. (2016). Psychotropic effects of Lactobacillus plantarum PS128 in early life-stressed and naïve adult mice. Brain research, 1631, 1–12.

[5] Liao, J. F., Cheng, Y. F., You, S. T., Kuo, W. C., Huang, C. W., Chiou, J. J., Hsu, C. C., Hsieh-Li, H. M., Wang, S., & Tsai, Y. C. (2020). Lactobacillus plantarum PS128 alleviates neurodegenerative progression in 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine-induced mouse models of Parkinson's disease. Brain, behavior, and immunity, 90, 26–46.