The gut in trauma.
The purpose of this review is to describe established and emerging mechanisms of gut injury and dysfunction in trauma, describe emerging strategies to improve gut dysfunction, detail the effect of trauma on the gut microbiome, and describe the gut-brain connection in traumatic brain injury.



Newer data suggest intraluminal contents, pancreatic enzymes, and hepatobiliary factors disrupt the intestinal mucosal layer. These mechanisms serve to perpetuate the inflammatory response leading to multiple organ dysfunction syndrome (MODS). To date, therapies to mitigate acute gut dysfunction have included enteral nutrition and immunonutrition; emerging therapies aimed to intestinal mucosal layer disruption, however, include protease inhibitors such as tranexamic acid, parenteral nutrition-supplemented bombesin, and hypothermia. Clinical trials to demonstrate benefit in humans are needed before widespread applications can be recommended.



Despite resuscitation, gut dysfunction promotes distant organ injury. In addition, postresuscitation nosocomial and iatrogenic 'hits' exaggerate the immune response, contributing to MODS. This was a provocative concept, suggesting infectious and noninfectious causes of inflammation may trigger, heighten, and perpetuate an inflammatory response culminating in MODS and death. Emerging evidence suggests posttraumatic injury mechanisms, such as intestinal mucosal disruption and shifting of the gut microbiome to a pathobiome. In addition, traumatic brain injury activates the gut-brain axis and increases intestinal permeability.
aDepartment of Medicine, Division of Pulmonary and Critical Care Medicine, Medical College of Wisconsin, Milwaukee, Wisconsin bDepartment of Surgery, University of Florida, Gainesville, Florida cDepartment of Surgery, Division of Trauma Surgery, University of Louisville, Louisville, Kentucky dDepartment of Surgery, Division of General Surgery, Oregon Health Sciences University, Portland, Oregon, USA.
Jayshil J
JJ
Patel
Martin D
MD
Rosenthal
Keith R
KR
Miller
Robert G
RG
Martindale
D003422:Critical Care; D016638:Critical Illness; D003428:Cross Infection; D006801:Humans; D007413:Intestinal Mucosa / Q000503:physiopathology*; D007422:Intestines / Q000503:physiopathology*; D009102:Multiple Organ Failure; D010539:Permeability; D014947:Wounds and Injuries / Q000150:complications*