Dysregulation of the Gut-Brain Axis, Dysbiosis and Influence of Numerous Factors on Gut Microbiota Associated Parkinson's Disease

Abstract

Background: Parkinson's disease (PD) has been one of the substantial social, medical concerns and, burdens of the present time. PD is a gradually devastating neurodegenerative disorder of the neurological function marked with α-synucleinopathy affecting numerous regions of the brain-gut axis, as well as the central, enteric, and autonomic nervous system. Its etiology is a widely disputed topic.

Objective: This review emphasizes to find out the correlation among the microbial composition and the observable disturbances in the metabolites of the microbial species and its impact on the immune response, which may have a concrete implication on the occurrence, persistence and, pathophysiology of PD via the gut-brain axis.

Methods: An in-depth research and the database was developed from the available peer-reviewed articles to date (March 2020) utilizing numerous search engines like PubMed, MEDLINE and, other internet sources.

Results: Progressively increasing shreds of evidence have proved the fact that dysbiosis in the gut microbiome plays a central role in many neurological disorders, such as PD. Indeed, a disordered microbiome-gut-brain axis in PD could be focused on gastrointestinal afflictions that manifest primarily several years prior to the diagnosis, authenticating a concept wherein the pathological pathway progresses from the intestine reaching the brain.

Conclusion: The microbiota greatly affects the bidirectional interaction between the brain and the gut via synchronized neurological, immunological, and neuroendocrine mechanisms. It can be concluded that a multitude of factors discussed in this review steadily induce the onset of dysbacteriosis that may exacerbate the etiologic mechanism of Parkinson's disease.

Keywords: Gut microbiota; TLRs; gastrointestinal tract; gut-brain axis; parkinson’s disease; α-synuclein.

Fig. (1)

The complicated crosstalks between GM and brain. (A higher resolution / colour version of this figure is available in the electronic copy of the article).

Fig. (2)

A summarized form of possible mechanisms through which altered microbiota sends signals to the brain affected with PD. . (A higher resolution / colour version of this figure is available in the electronic copy of the article).