Investigating the Roles of Gut Microbiome in the Progression of Neurodegenerative Diseases: Alzheimer's, Parkinson's, and Amyotrophic Lateral Sclerosis (ALS)

Abstract

Neurodegenerative diseases (NDs), such as Alzheimer’s disease (AD), Parkinson’s disease (PD), and Amyotrophic Lateral Sclerosis (ALS), pose global health burdens due to their incurable and degenerative nature. Emerging evidence highlights the complex interplay between the gut microbiome and the central nervous system (CNS), revealing novel mechanisms of ND pathogenesis and progression. This review integrates current literature, correlation analyses, and inferential statistics to elucidate the impact of gut microbiome dysbiosis on NDs and identify potential diagnostic biomarkers and therapeutic targets. The gut-brain axis (GBA), a bidirectional communication network between the gut and the brain, modulates neurological function and disease outcomes. Correlation analyses demonstrated significant associations between gut microbiome perturbations and ND parameters, implying a causal role for gut dysbiosis in ND pathogenesis. Inferential statistics revealed distinct microbial profiles between ND cohorts and healthy controls, indicating a shared gut dysbiosis across diverse NDs. Studies investigating microbial taxa, metabolites, and signaling pathways have provided insights into the molecular mechanisms underlying gut microbiome-mediated effects on neurodegeneration. Elucidating the reciprocal interactions between the gut microbiome and the host physiology is essential for deciphering the GBA’s role in NDs. Despite advances, knowledge gaps remain. Longitudinal studies are required to monitor gut microbiome dynamics over ND progression. Mechanistic studies are needed to establish how gut microbiome composition affects disease. Methodological standardization for gut microbiome assessment is imperative for rigorous research. Future endeavors should aim to translate findings into clinical applications to exploit microbiome-based interventions for enhanced neurological outcomes in NDs.