Identifying Treatments for Taste and Smell Disorders: Gaps and Opportunities

Abstract

The chemical senses of taste and smell play a vital role in conveying information about ourselves and our environment. Tastes and smells can warn against danger and also contribute to the daily enjoyment of food, friends and family, and our surroundings. Over 12% of the US population is estimated to experience taste and smell (chemosensory) dysfunction. Yet, despite this high prevalence, long-term, effective treatments for these disorders have been largely elusive. Clinical successes in other sensory systems, including hearing and vision, have led to new hope for developments in the treatment of chemosensory disorders. To accelerate cures, we convened the “Identifying Treatments for Taste and Smell Disorders” conference, bringing together basic and translational sensory scientists, health care professionals, and patients to identify gaps in our current understanding of chemosensory dysfunction and next steps in a broad-based research strategy. Their suggestions for high-yield next steps were focused in 3 areas: increasing awareness and research capacity (e.g., patient advocacy), developing and enhancing clinical measures of taste and smell, and supporting new avenues of research into cellular and therapeutic approaches (e.g., developing human chemosensory cell lines, stem cells, and gene therapy approaches). These long-term strategies led to specific suggestions for immediate research priorities that focus on expanding our understanding of specific responses of chemosensory cells and developing valuable assays to identify and document cell development, regeneration, and function. Addressing these high-priority areas should accelerate the development of novel and effective treatments for taste and smell disorders.

Surveying Chemosensory Dysfunction in COVID-19

“…Since reports began to appear in March of this year that COVID-19 is accompanied by smell and taste loss, numerous papers that address this phenomenon have been published or prepublished (see Pellegrino et al 2020 in the July issue of Chemical Senses for a comprehensive review). The lack of wide-spread testing for the highly infectious and deadly SARS-CoV-2 virus in much of the world led scientists and clinicians to focus urgently on smell and taste deficits as possible early indicators of COVID-19 and to gain insight into how the virus enters the body in the upper airway ( Mainland et al 2020 ; Xu et al 2020 ; Zou et al 2020 ). In their review, Pellegrino et al (2020 ) point to the need for studies to provide 1) better quantification of the occurrence of the dysfunctions, 2) improved understanding of the relationship among dysfunctions of olfaction, taste, and chemesthesis, the 3 chemosensitive systems that serve the nose and mouth, and 3) to determine the persistence of the chemosensory losses following recovery from COVID-19.…”

COVID-19 as a worldwide selective event and bitter taste receptor polymorphisms: An ecological correlational study

“…Treatment options for COVID-19 are not completely provided, but stem cell therapies have already shown efficiency in treating inflammatory responses in patients with COVID-19 [ 50 ]. Unless the stem cells of the oral cavity are not severely impaired, the olfactory system may have the substantial regenerative ability, contributing to spontaneous odor perception recovery [ 51 ]; So, stem cell therapies can be queried for smell and taste perception loss treatment in COVID-19. It is possible to provide a specific technique to recognize signaling pathways that trigger the stimulation and neurogenesis of olfactory stem cells and thus utilize the intrinsic ability of the olfactory resident stem cells for recovery [ 52 ].…”

NIH Workshop Report: sensory nutrition and disease

“…Few clinical studies have assessed chemosensory measures or clinical guidelines for treatments, and, as aforementioned, we need to optimize rapid, standardized measures for the clinical setting that could extend to nonclinical settings. In addition, existing treatment strategies for taste and smell disorders are limited and often ineffective ( 156 ). More studies are also needed to connect chemosensory alterations to other clinical disorders such as diabetes, obesity, and cancer, and we need increased support for chemosensory clinician-scientists to foster interdisciplinary collaborations.…”