The major adaptive systems of the body (nervous, endocrine and immune) do not operate in isolation, these systems are in constant communication, collaborating and coordinating their actions to maintain optimal physiological functions and defense against external threats. In this context the divisions between nervous, immune and endocrine systems are artificial and in effect they form a neuro-immuno-endocrine super-system.
Disruption of any component of this super-system can result in sub-optimal adaptive responses and diminished defenses, leading to disease. Hence immune disorders may have origins in disrupted neuroendocrine control and neurological symptoms may result from dysregulated immunity. By the same token, potential therapeutic approaches to immune conditions may include modulation of neural and endocrine responses.
We now recognize that commensal microbes are integrated into the neuro-immuno-endocrine super-system; acting on individual components, and communication between components, to influence adaptive responses and multiple aspects of physiology. While this adds to the complexity of an already intricate communication system, it also opens the possibility of identifying novel strategies to harness the therapeutic potential of regulating neuro-immuno-endocrine responses.