Non-specific stimulation of host defenses against a bacterial challenge in malnourished hosts.

We have studied the effects of non-specific enhancement of host defenses in malnourished mice using muramyl dipeptide (MDP). The challenge, consisting of a bacteria laden suture, simulates a surgical wound infection. Adult mice were subjected either to a 48-h period of acute starvation or to a 2 week period of protein deprivation. In each type of malnutrition, mice treated with MDP 24 h before the bacterial challenge had statistically lower local and systemic bacterial recovery, with a corresponding improvement in short term survival, than did untreated controls. MDP enhances local bacterial containment, thereby substantially reversing the detrimental effects of malnutrition on host defences.