The Role of the human microbiome in neurodegenerative diseases: A Perspective.

Advances in diagnostics, therapeutics, and large-scale clinical studies have significantly expanded our understanding how human health is shaped by the microorganisms that colonize the body since birth. This article explores the rapidly evolving field of human microbiome research, focusing upon how microbial communities influence neurological health and contribute to the development of neurodegenerative diseases (NDs). Multiple factors, including age, lifestyle, and immunological memory, are recognized as major determinants of an individual's microbiome composition, which in turn can influence the onset and the progression of disorders such as Alzheimer's disease, Parkinson's disease, Huntington's disease, and amyotrophic lateral sclerosis. These conditions have been linked to mechanisms including the aggregation of pathogenic proteins (e.g., amyloid-β and α-synuclein), inflammation driven by activation of the Toll-like receptor (TLR) signaling pathway, the NLRP3 inflammasome, as well as the modulatory effect of microbial metabolites such as short-chain fatty acids (SCFAs) and lipopolysaccharides (LPS). The article also highlights ongoing research and emerging strategies aimed at leveraging the human microbiome for better diagnosis, and management of NDs.