Abstract
The human microbiota is composed of trillions of microbial cells inhabiting the oral cavity, skin, gastrointestinal (GI) tract, airways, and reproductive organs. The gut microbiota is composed of dynamic communities of microorganisms that communicate bidirectionally with the brain via cytokines, neurotransmitters, hormones, and secondary metabolites, known as the gut microbiota–brain axis. The gut microbiota–brain axis is suspected to be involved in the development of neurological diseases, including Alzheimer’s disease (AD), Parkinson’s disease, and Autism Spectrum Disorder. AD is an irreversible, neurodegenerative disease of the central nervous system (CNS), characterized by amyloid-β plaques, neurofibrillary tangles, and neuroinflammation. Microglia and astrocytes, the resident immune cells of the CNS, play an integral role in AD development, as neuroinflammation is a driving factor of disease severity. The gut microbiota–brain axis is a novel target for Alzheimer’s disease therapeutics to modulate critical neuroimmune and metabolic pathways. Potential therapeutics include probiotics, prebiotics, fecal microbiota transplantation, and dietary intervention. This review summarizes our current understanding of the role of the gut microbiota–brain axis and neuroinflammation in the onset and development of Alzheimer’s disease, limitations of current research, and potential for gut microbiota–brain axis targeted therapies.
Highlights
The human microbiota, the aggregate of all bacterial, viral, fungal, and archaeal cells that inhabit the human body, consists of 1–1.5× more microbial cells than human cells (~1014 ) [1]
We have summarized the role of the gut microbiota–brain axis as an integral part of disease pathogenesis
Growing evidence supports bidirectional communication between the central nervous system (CNS) and the gut microbiota; studies demonstrate that the microbiota shapes Alzheimer’s disease (AD) pathologies and neuroinflammation, and AD pathogenesis modulates the gut microbiota composition
Summary
The human microbiota, the aggregate of all bacterial, viral, fungal, and archaeal cells that inhabit the human body, consists of 1–1.5× more microbial cells than human cells (~1014 ) [1]. Recent studies of the human microbiome demonstrate a myriad of roles that these microbes play in host health, including host immune function [3,4], protection against pathogen colonization [5], and host metabolism [6]. Depleted systemic estrogens are linked to cognitive decline, memory loss, and reduced fine motor skills [18,19] Another key player in the gut microbiota–brain axis is the vagus nerve, which allows for direct communication via neurotransmitters between the CNS and the enteric nervous system (ENS) [20]. One study demonstrated that CD-induced changes in the gut microbiome and neurological disease development can be improved through a gluten-free diet (GFD). Could this statement hold the truth, even after 2500 years? In this review, we will discuss the current understanding of the role of the gut microbiota–brain axis in AD and provide commentary on potential mechanisms for AD pathogenesis
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
