In a study involving nematode worms, scientists found that when these worms were exposed to a specific compound released by harmful bacteria, it triggered the activation of a neural pathway. This activation led to an increase in the lifespan of the worms and a reduction in protein aggregation, which is known to be a contributing factor in the development of neurodegenerative illnesses.
An organism’s reaction to repugnant odors can be an indicator of the organism’s capacity to protect itself from harmful substances and live longer. This at least is what happens in the case of nematodes of the species Caenorhabditis elegans.
— Read more in The Scent of Longevity: How Smelling Harmful Substances May Prolong Life at SciTechDaily.