The microbiota-microglia axis: A novel clue for diet and brain health

Background

Microglia are resident myeloid cells of the brain and exert essential roles in maintaining the normal physiological function of the brain. Microglia dysfunction was related to the initiation and development of neuroinflammation and neuropsychiatric disorders. It has been established that the gut microbiota controls the immunological activation response of microglia as well as their maturation and function in the brain. Nevertheless, exactly how the gut microbiota affects the function of brain microglia remains unclear.

Scope and approach

Herein, we highlighted the essential function that the gut microbiota plays in regulating the development and activity of microglia. Furthermore, this article provided details on how gut microbiota affects microglia through metabolic, neurological, immune, and endocrine routes. Importantly, based on the microbiota-microglia axis, we discussed possible mechanisms underlying the effects of diet on microglia through gut microbiota, including the dietary structure, neuroactive dietary components polyphenols and polysaccharides.

Key findings and conclusions

The gut microbiota interact with microglia to affect the maturation, development, and function of microglia. Microglia shape the gut microbiota and react dynamically to dietary nutrition. Dietary components of polyphenols and polysaccharides have a direct or indirect impact on microglia through gut microbiota and subsequently relieve neuroinflammation. Therefore, communication between gut microbiota and microglia offers a fresh perspective on how nutrition affects brain function and serves as a theoretical basis for the development of functional foods that have neuroprotective properties.