Taste Bud Changes May Explain Long-Lasting COVID-Related Taste Loss
Researchers examined 28 patients whose sense of taste remained disturbed more than a year after COVID-19, finding clearly abnormal taste scores in eight of them. In tissue from 20 participants, they observed lower levels of mRNA for PLCβ2, a protein involved in sweet, bitter, and umami signaling, along with structural changes in taste buds. Salty and sour perception was largely unaffected.
The study focused on 28 non-hospitalized adults whose taste remained altered for over a year after COVID-19. Eight showed clearly abnormal taste test results, and eleven specifically struggled with sweet, bitter, or umami flavors, while salty and sour detection was mostly preserved.
Taste tissue from 20 participants revealed less mRNA for PLCβ2, a signaling protein that boosts sweet, bitter, and umami messages. Microscopy also showed disorganized taste-cell arrangements in some cases. Researchers suggest both weakened molecular signaling and structural changes may underlie enduring taste symptoms.
For people with long-lasting COVID-related taste changes, everyday eating and food enjoyment could remain affected, potentially influencing appetite, nutrition, and social meals. Because salty and sour perception often persists, the burden may differ among patients. Clinicians may use this evidence to better recognize such cases as having a biological basis, which could support clearer explanations, monitoring, and future targeted treatments.