| Demonstrations with radioimmunoassay and immunohistochemistry techniques have given rise to the concept of the gut-brain axis. Several studies suggest that brain function, including cognitive processing, responds to changes in nutrients. Many behaviour disturbances and diseases are thought to have their origin in a metabolic dysfunction due to consumption and absorption of certain food products and their metabolites and this paper will focus on the role of the gut and its interaction with neuromodulatory metabolites in common central nervous system related disorders. |