The microbiota-microglia axis in central nervous system disorders.

Area of Science:

• Neuroimmunology
• Microbiology
• Central Nervous System (CNS) Research

Background:

• Microglia are the primary immune cells in the CNS, crucial for brain health and disease.
• Microglial function is influenced by various factors, including host and environmental elements.
• The gut microbiota, residing in the digestive system, significantly impacts host physiology.

Purpose of the Study:

• To review the intricate relationship between the host microbiota and the CNS.
• To highlight the role of gut microbiota in modulating microglial function in both health and disease.
• To introduce and define the concept of the "microbiota-microglia axis."

Main Methods:

• Literature review of recent findings on microbiota-CNS interactions.
• Analysis of studies investigating microglial responses to microbial metabolites like short-chain fatty acids (SCFAs) and aryl hydrocarbon receptor (AhR) ligands.
• Synthesis of evidence linking gut microbial composition to CNS conditions.

Main Results:

• Gut microbiota composition and metabolites (e.g., SCFAs, AhR ligands) directly influence microglial activation states and functions.
• The gut microbiota acts as a critical environmental factor shaping microglial properties in the CNS.
• Dysbiosis or alterations in gut microbiota are implicated in the pathogenesis of various CNS diseases.

Conclusions:

• The gut microbiota plays a pivotal role in regulating microglial function, establishing the "microbiota-microglia axis."
• Understanding this axis is crucial for developing novel therapeutic strategies for CNS disorders.
• Targeting the gut microbiota may offer a promising avenue for managing neuroinflammatory and neurodegenerative diseases.