Microbiota Dysbiosis in Parkinson Disease—In Search of a Biomarker

Abstract

Numerous studies have highlighted the role of the gastrointestinal system in Parkinson disease pathogenesis. It is likely triggered by proinflammatory markers produced by specific gut bacteria. This review’s aim is to identify gut bacterial biomarkers of Parkinson disease. A comprehensive search for original research papers on gut microbiota composition in Parkinson disease was conducted using the PubMed, Embase, and Scopus databases. Research papers on intestinal permeability, nasal and oral microbiomes, and interventional studies were excluded. The yielded results were categorized into four groups: Parkinson disease vs. healthy controls; disease severity; non-motor symptoms; and clinical phenotypes. This review was conducted in accordance with the PRISMA 2020 statement. A total of 51 studies met the eligibility criteria. In the Parkinson disease vs. healthy controls group, 22 bacteria were deemed potentially important. In the disease severity category, two bacteria were distinguished. In the non-motor symptoms and clinical phenotypes categories, no distinct pathogen was identified. The studies in this review report bacteria of varying taxonomic levels, which prevents the authors from reaching a clear conclusion. Future research should follow a unified methodology in order to identify potential biomarkers for Parkinson disease.

Gut Microbial Alteration in MPTP Mouse Model of Parkinson Disease is Administration Regimen Dependent

“…This suggests that repeated injection could have an impact on microbial composition as well. Meta-analysis and systematic reviews performed recently revealed that although gut microbial composition detected in PD patients may vary among different studies, shared alterations in gut microbiota of PD have been observed (Hill et al 2021 ; Shen et al 2021 ; Nowak et al 2022 ). Abundance of Akkermansia , Verrucomicrobiota, and Alistipes have found to be increased in PD patients while decrease in level of Lachnospiraceae and Prevotellaceae have detected.…”

The pathobiological basis of depression in Parkinson disease: challenges and outlooks

“…Gut microbiotic changes that play a crucial role in the bidirectional communication between the gut and the brain (Klann et al 2022 ) with a close link between multiple movement disorders and gastrointestinal dysfunction (Talman and Pfeiffer 2022 ), suggest that the gut microbes may shape neuronal development, modulate neurotransmission and affect behavior, have been associated with the pathomechanism of DPD (Dogra et al 2022 ; Mendonça et al 2020 ; Moustafa et al 2021 ; Socala et al 2021 ) (Felice et al 2016 ; Jones et al 2021 ; Tan et al 2022 ; Xie et al 2022 ). There is increasing evidence for the highly complex relationship between the gut and the brain in PD, including the potential role of the vagus nerve, αSyn deposition in the enteric nervous system, related to intestinal permeability, autonomic dysfunction, inflammation, neural immune system and the gut microbiome (Nowak et al 2022 ; Tan et al 2022 ; Tansey et al 2022 ; Warnecke et al 2022 ). Decreased fecal bacterially produced butyrate is related to epigenetic changes in leucocytes and neurons from PD patients and the severity of depressive symptoms (Xie et al 2022 ).…”

Gut-brain axis as a key aspect of clinical conditions

“…16 The pursuit of biomarkers for this neurological condition also includes a variety of non-motor symptoms (NMS), which are less recognizable but highly prevalent. 17 Since mobility impairment and its eventual development often tend to be the most obvious PD symptoms, they are frequently overlooked during patient screening. However, the disease's non-motor symptoms, such as hyposmia and constipation, have been able to provide light on its potential etiology.…”

“…However, the disease's non-motor symptoms, such as hyposmia and constipation, have been able to provide light on its potential etiology. 18 As stated by Nowak et al 17 faster diagnoses might be made by identifying specific PD risk biomarkers, ideally, before the motor phase of the illness emerges in these individuals. This could open the possibility for early medical monitoring and a more comprehensive approach to mitigating the symptoms of prodromal Parkinson's disease.…”