The Association Between the Gut Microbiota and Parkinson's Disease, a Meta-Analysis

Abstract

Patients with Parkinson's disease (PD) were often observed with gastrointestinal symptoms, which preceded the onset of motor symptoms. Neuropathology of PD has also been found in the enteric nervous system (ENS). Many studies have reported significant PD-related alterations of gut microbiota. This meta-analysis was performed to evaluate the differences of gut microbiota between patients with PD and healthy controls (HCs) across different geographical regions. We conducted a systematic online search for case-control studies detecting gut microbiota in patients with PD and HCs. Mean difference (MD) and 95% confidence interval (CI) were calculated to access alterations in the abundance of certain microbiota families in PD. Fifteen case-control studies were included in this meta-analysis study. Our results showed significant lower abundance levels of Prevotellaceae (MD = −0.37, 95% CI = −0.62 to −0.11), Faecalibacterium (MD = −0.41, 95% CI: −0.57 to −0.24), and Lachnospiraceae (MD = −0.34, 95% CI = −0.59 to −0.09) in patients with PD compared to HCs. Significant higher abundance level of Bifidobacteriaceae (MD = 0.38, 95%; CI = 0.12 to 0.63), Ruminococcaceae (MD = 0.58, 95% CI = 0.07 to 1.10), Verrucomicrobiaceae (MD = 0.45, 95% CI = 0.21 to 0.69), and Christensenellaceae (MD = 0.20, 95% CI = 0.07 to 0.34) was also found in patients with PD. Thus, shared alterations of certain gut microbiota were detected in patients with PD across different geographical regions. These PD-related gut microbiota dysbiosis might lead to the impairment of short-chain fatty acids (SCFAs) producing process, lipid metabolism, immunoregulatory function, and intestinal permeability, which contribute to the pathogenesis of PD.

Desulfovibrio Bacteria Are Associated With Parkinson’s Disease

“…Further, Akkermansia muciniphila and Bifidobacterium , abundant inhabitants of the human gut, can degrade mucin ( Derrien et al., 2008 ; Ruas-Madiedo et al., 2008 ). Several studies on gut microbiota in PD have shown increases in the relative abundance of these bacteria ( Chiang and Lin, 2019 ; Shen et al., 2021 ). Bifidobacteria are commonly available as commercial products, and their abundance in the gut is reported to correlate to the levodopa dose in PD ( Wallen et al., 2020 ).…”

“…Since 2015, changes in gut microbiota compositions in PD have been found in several large-scale case-control studies ( Scheperjans et al., 2015 ; Shen et al., 2021 ). Composition changes concerning the phylum level are difficult to establish due to high variability in the relative abundances of bacterial phyla in PD studies ( Chiang and Lin, 2019 ).…”

“…Composition changes concerning the phylum level are difficult to establish due to high variability in the relative abundances of bacterial phyla in PD studies ( Chiang and Lin, 2019 ). Concerning the family level of bacteria, a recent meta-analysis on fourteen case-control studies showed, by 95% confidence interval analysis, significantly increased relative abundances of Verrucomicrobiaceae, Bifidobacteriaceae , and Christesenellaceae in PD gut microbiota ( Shen et al., 2021 ). At the genus level, opportunistic pathogens including Porphyromonas , Prevotella and Corynebacterium were found to be elevated in PD in a microbiome-wide association study ( Wallen et al., 2020 ).…”

Regulation of Neurotransmitters by the Gut Microbiota and Effects on Cognition in Neurological Disorders

“…Meanwhile, PD is characterized by the dysregulation of the dopamine system [ 60 ]. Increase of Akkermansia , Catabacter , Lactobacillus , Bifidobacterium , Bifidobacteriaceae, Ruminococcaceae, Verrucomicrobiaceae, Christensenellaceae, and decrease of Roseburia , Faecalibacterium, Lachnospiraceae ND3007 group, Prevotellaceae, Blautia , Coprococcus , and Lachnospira have been observed in PD patients [ 17 , 90 , 91 ]. The metabolism of l -DOPA and dopamine is associated with the abundance of Enterococcus faecalis in patients with PD [ 92 ].…”

The Association Between the Gut Microbiota and Systemic Lupus Erythematosus, a Meta-Analysis

“…According to the analysis, the relative abundance of this ora in patients with SLE is higher than that in healthy people. The result might indicate that there may be bacteria can reconstruct gut homeostasis by potential compensatory regulation [42,51] . Furthermore, there was no signi cant difference in Lachnospiraceae and Bacteroides between SLE patients and healthy controls in the included study.…”