The pharmacological role of probiotics in reducing the symptoms of Parkinson's disease
The pharmacological role of probiotics in reducing the symptoms of Parkinson's disease
Mahdi Soltanian,1,*Zeinab Faghfoori,2
1. Student Research Committee, Faculty of Nutrition, Semnan University of Medical Sciences, Semnan, Iran 2. Food Safety Research Center (Salt), Semnan University of Medical Sciences, Semnan, Iran
Introduction: Parkinson’s disease (PD) is the second most common neurodegenerative disease worldwide that affects 3.7% of the population over 65 years of age; it is a progressive degeneration of dopaminergic neurons that are present in the substantia nigra pars compacta (SNPC) with a deficiency of dopamine, that can lead to altered motor movement. Based on recent evidence, due to the strong correlation between the gut-brain axis and PD, there is a positive relation between the consumption of probiotics with the improvement of Parkinson's disease symptoms through different pathways and mechanisms.
Methods: Studies published from the beginning to 2023 analyzing the effect of probiotics on PD were searched by searching Google Scholar, Pubmed, Scopus and Web of Science. Among the screened articles, related articles were reviewed.
Results: Probiotics play a beneficial role in the pathways that lead to the degeneration of dopaminergic neurons and ultimately the exacerbation of PD symptoms; For example, in the PARK-2 gene mutation, which leads to the lack of expression of the E3 ubiquitin ligase enzyme gene and the accumulation of alpha-synuclein, Saccharomyces boulardi and Lactococcus lactis probiotics, play a role in increasing the expression of this enzyme. As another example, SCFAs play a role in inhibiting DDT and ROTENONE pesticides, which cause the degeneration of dopaminergic neurons. In addition, considering that the only way to improve the symptoms (Especially movement disorders) in this disease is to increase the levels of dopamine, SCFAs have shown their beneficial effect here by inhibiting the enzymes that break down dopamine (MAO-B and COMT). It has been found that the use of probiotics increases the production of anti-inflammatory factors and decreases the gene expression of inflammatory factors, as well as reducing the accumulation of ROS and as a result, neuroinflammation, which is one of the main reasons for PD, is prevented. Our review shows that probiotics can be used to improve constipation and motor symptoms for patients with Parkinson’s constipation, possibly by reducing the inflammatory response and improving gut-brain axis neuron function. Probiotics can directly stimulate electrical signals in the ENS and dorsal motor nucleus of the vagus (DMV) by transmitting signals through the vagus nerves to affect the center of the brain, thus reducing the accumulation of α-syn and reducing motor deficits in PD patients. According to research, ghrelin levels (which play a role in maintaining and protecting the normal function of nigrostriatal dopamine) is reduced in PD patients, and with Prevotella, ghrelin concentrations return to normal.
Conclusion: According to the results obtained from the present studies (considering the gut-brain axis), the consumption of probiotic supplements in a specified type and dose can have positive effects on the symptoms of Parkinson's disease (especially constipation). More studies can help to understand and prove the mechanisms of the effects of probiotics on Parkinson's disease.