LAL reacts with bacterial endotoxin lipopolysaccharide (LPS), which is a membrane component of gram-negative bacteria. A component of lipopolysaccharide, also called endotoxin. Suspected causes include abnormal responses to bacteria or bacterial endotoxin, or a hypersensitivity to food. The release of endotoxin is the mechanism by which Gram-negative sepsis provokes DIC. Plasma may also be given with the intent of neutralizing endotoxin. As an endotoxin, LOS provokes inflammation. The body's response to an endotoxin can involve severe inflammation. The "N. meningitidis" bacterium is surrounded by a slimy outer coat that contains disease-causing endotoxin. It, however, contained pertussis endotoxin (surface lipooligosaccharide) and produced side effects. Ultraendurance athletes have been found to have significantly increased plasma endotoxin levels. Lipooligosaccharide (LOS) is an endotoxin that provokes an immune response. However, surgical stress reduced mortality from endotoxin shock. This facilitates the absorption of the gut-produced endotoxin into the portal circulation. They then identified TNF as a mediator of lethal endotoxin poisoning. This reaction was experimented using "Neisseria meningitidis" endotoxin.