Alzheimer's disease and symbiotic microbiota: an evolutionary medicine perspective.
Molly M FoxDelaney A KnorrKacey M HaptonstallPublished in: Annals of the New York Academy of Sciences (2019)
Microorganisms resident in our bodies participate in a variety of regulatory and pathogenic processes. Here, we describe how etiological pathways implicated in Alzheimer's disease (AD) may be regulated or disturbed by symbiotic microbial activity. Furthermore, the composition of symbiotic microbes has changed dramatically across human history alongside the rise of agriculturalism, industrialization, and globalization. We postulate that each of these lifestyle transitions engendered progressive depletion of microbial diversity and enhancement of virulence, thereby enhancing AD risk pathways. It is likely that the human life span extended into the eighth decade tens of thousands of years ago, yet little is known about premodern geriatric epidemiology. We propose that microbiota of the gut, oral cavity, nasal cavity, and brain may modulate AD pathogenesis, and that changes in the microbial composition of these body regions across history suggest escalation of AD risk. Dysbiosis may promote immunoregulatory dysfunction due to inadequate education of the immune system, chronic inflammation, and epithelial barrier permeability. Subsequently, proinflammatory agents-and occasionally microbes-may infiltrate the brain and promote AD pathogenic processes. APOE genotypes appear to moderate the effect of dysbiosis on AD risk. Elucidating the effect of symbiotic microbiota on AD pathogenesis could contribute to basic and translational research.
Keyphrases
- endothelial cells
- cognitive decline
- oxidative stress
- healthcare
- white matter
- transcription factor
- induced pluripotent stem cells
- multiple sclerosis
- escherichia coli
- randomized controlled trial
- quality improvement
- staphylococcus aureus
- resting state
- clinical trial
- gene expression
- patient safety
- antimicrobial resistance
- pluripotent stem cells
- functional connectivity
- subarachnoid hemorrhage
- drug induced
- cystic fibrosis
- mild cognitive impairment
- insulin resistance