The microbiota-gut-brain axis: A key regulator of neural function across the lifespan

Abstract Text:

The microbiota-gut-brain axis is emerging as a research area of increasing interest for those investigating the biological and physiological basis of neurodevelopmental, age-related and neurodegenerative disorders. The routes of communication between the gut and brain include the vagus nerve, the immune system, tryptophan metabolism, via the enteric nervous system or by way of microbial metabolites such as short chain fatty acids. Studies in animal models have shown that the development of an appropriate stress response is dependent on the microbiota. Developmentally, a variety of factors can impact the microbiota in early life including mode of birth delivery, antibiotic exposure, mode of nutritional provision, infection, stress as well as host genetics.  At the other extreme of life, individuals who age with considerable ill health tend to show narrowing in microbial diversity and a proinflammatory phenotype. Stress can significantly impact the microbiota-gut-brain axis at all stages across the lifespan. Recently, the gut microbiota has been implicated in a variety of conditions including autism, schizophrenia and Parkinson’s disease. Moreover, fundamental brain processes from adult hippocampal neurogenesis to prefrontal cortex myelination to microglia activation have been recently shown to be regulated by the microbiome. Further studies will focus on understanding the mechanisms underlying such brain effects.

Keywords: myelin, neurodevelopment, psychobiotic, stress