Role of Odour Perception in Health and Disease

The sensory system gauges the external environment to maintain homeostasis and regulate the behaviour of animals. One of the sensory modalities, olfaction, has gathered considerable attention in recent years due to its direct impact on the survival of animals. Research conducted on human, vertebrate and invertebrate model systems has revealed that the odour perception ability of an animal not only helps in the identification of palatable, stale or toxic items but also regulates a wide range of physiological functions such as appetite, lipid storage, metabolic homoeostasis, reproduction, lifespan and immunity. Moreover, olfactory impairments are often observed at early stages of disease and can be associated with progression, susceptibility or diagnosis of various systemic and neurological diseases. A growing number of evidence indicates that odorant molecules present in breath, body fluids or skin of patients are manifestations of underlying pathological conditions. Screening of such samples is being done for the detection of human diseases by leveraging the exceptional olfactory ability of certain animal species or artificial devices mimicking the olfactory ability of such animals. Understanding the link between olfaction and health may help in enhancing longevity, improving the diagnosis and treatment of various diseases. The current review for the first time describes the recent research conducted on human and animal models, depicting the role of olfaction in health and longevity and how olfactory function might be linked to disease diagnosis, susceptibility and treatment.