Disgusting odors trigger the oral immune system


 Recent research has characterized the behavioral defense against disease. In particular the detection of sickness cues, the adaptive reactions (e.g., avoidance) to these cues, and the mediating role of disgust have been the focus. A presumably important but less investigated part of a behavioral defense is the immune system response of the observer of sickness cues. Odors are intimately connected to disease and disgust, and research has shown how olfaction conveys sickness cues in both animals and humans. This study aims to test whether odorous sickness cues (i.e., disgusting odors) can trigger a preparatory immune response in humans. We show that subjective and objective disgust measures, as well as TNFαlevels in saliva increased immediately after exposure to disgusting odors in a sample of 36 individuals. Altogether, these results suggest a collaboration between behavioral mechanisms of pathogen avoidance in olfaction, mediated by the emotion of disgust, and mechanisms of pathogen elimination facilitated by inflammatory mediators.