Figure 2.

Microbiome influence on microglia and astrocyte function in health, age, and neuropathology. Multiple factors affect an individual’s microbiome composition including diet, age, and disease. In the distal intestine, gut metabolites can cross the gut epithelium and modulate the immune system, which can influence the function of microglia and astrocytes in health, age, and neurodegenerative diseases. Functions of microglia and astrocytes that are altered in mice who have had their microbiome altered, contain a microbiome or lack thereof have been identified. Aβ, amyloid-β; GF, germ-free; ABX, antibiotic; AD, Alzheimer’s disease; EAE, experimental autoimmune encephalomyelitis; CNS, central nervous system; DC, dendritic cell; HF, high-fat; TMAO, trimethylamine N-oxide; AHR, aryl hydrocarbon receptor. *Created with Biorender.com.