“The ecosystem of the human gut consists of trillions of bacteria forming a bioreactor that is fueled by dietary macronutrients to produce bioactive compounds. These microbiota-derived metabolites signal to distant organs in the body, which enables the gut bacteria to connect to the immune and hormone system, to the brain (the gut–brain axis)…..”
“This microbe–host communication is essential to maintain vital functions…..”
“….the gut microbiota has been associated with a number of diseases, ranging from obesity and inflammatory diseases to behavioral and physiological abnormalities associated with neurodevelopmental disorders.”
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B.O.Schroeder, F.Backhed
Signals from the gut microbiota to distant organs in physiology and disease
Nature Medicine — Volume 22 #10, October 2016 — page 1079

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“The diverse collection of microorganisms that inhabit the gastrointestinal tract, collectively called the gut microbiota, profoundly influences many aspects of host physiology, including nutrient metabolism, resistance to infection and immune system development.”
“….critical role for the gut microbiota in orchestrating brain development and behavior, and the immune system is emerging as an important regulator of these interactions.”
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Intestinal microbes modulate the maturation and function of tissue-resident immune cells in the central nervous system. Microbes also influence the activation of peripheral immune cells, which regulate responses to neuroinflammation, brain injury, autoimmunity and neurogenesis.”
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Accordingly, both the gut microbiota and immune system are implicated in the etiopathogenesis or manifestation of neurodevelopmental, psychiatric and neurodegenerative diseases, such as autism spectrum disorder, depression and Alzheimer’s disease.”
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T.C.Fung, et al
Interactions between the microbiota, immune and nervous systems in health and disease
Nature Neuroscience — Volume 20 #2 February 2017 — page 145

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