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Study Identifies Taste-Cell Signaling Defect Behind Long COVID Taste Loss

Researchers link prolonged taste loss to a discrete taste-cell signaling deficit that could guide targeted therapies.

Overview

  • Published in Chemical Senses, the study reports reduced PLCβ2 mRNA in taste receptor cells from patients with more than a year of post-COVID taste disturbances.
  • The defect selectively weakens sweet, bitter and umami signaling, while salty and sour remain largely intact because they use different pathways.
  • Among 28 non-hospitalized participants, 8 had clearly abnormal objective taste-test scores and 11 specifically reported loss of PLCβ2-dependent tastes.
  • Biopsies from 20 subjects showed mostly preserved taste-bud structure with occasional disorganization in some patients.
  • The authors note that signaling disruptions can persist beyond the normal 2–4 week turnover of taste cells and call for studies on reversibility and targeted treatments.