The Relationship Between Gut Microbiota and Neurodegenerative Diseases: A Meta-Analysis

Abstract

Background: Emerging evidence suggests that gut microbiota may influence
the pathogenesis of neurodegenerative diseases through the gut-brain axis. This
study aims to analyze the relationship between gut microbiota composition and
neurodegenerative conditions, including Alzheimer's disease (AD), Parkinson's
disease (PD), and amyotrophic lateral sclerosis (ALS).
Methods: A systematic review and meta-analysis were conducted, including 30
studies published between 2015 and 2023, with a total of 4,500 participants.
Metrics such as gut microbiota diversity, abundance of specific bacterial
genera, and associations with disease progression were evaluated.
Results: Neurodegenerative diseases were associated with reduced gut
microbiota diversity (mean difference: -1.25, 95% CI: -1.60 to -0.90, p < 0.01)
and an increased prevalence of pathogenic bacteria like Escherichia coli.
Beneficial bacteria such as Bacteroides and Lactobacillus were significantly
reduced in patients with AD and PD. A positive correlation was observed
between gut dysbiosis and biomarkers of neuroinflammation.
Conclusion: This meta-analysis supports the hypothesis that gut microbiota
alterations contribute to neurodegenerative disease pathogenesis. Modulating
gut microbiota through probiotics, prebiotics, or dietary interventions holds
promise as a therapeutic strategy.