Patients undergoing major surgery, trauma and burns are prone to develop an exacerbated inflammatory response, which is potentially lethal to the individual. Recently our group demonstrated that administration of high fat feeding prior to hemorrhagic shock attenuates severe inflammation, gut barrier loss and hepatic damage. High fat feeding releases cholecystokinin in the gut, which stimulates the autonomous nervous system and subsequently activates the efferent vagus nerve. The activated efferent fibers inhibit tissue macrophages via binding of acetylcholine to the alpha7-nicotinergic receptor. In this study the cholecystokinin release in healthy volunteers is monitored in response to low fat and high fat food products.