# Taste Bud Changes Found in Long COVID Patients with Lingering Taste Loss

> A study published on January 29, 2026, revealed molecular and structural abnormalities in the taste buds of individuals experiencing persistent taste loss more than a year after recovering from COVID-19.

By PrimaryBrief newsroom · Published 2026-10-19T13:15:08.766950Z
Canonical: https://primarybrief.com/article/taste-bud-changes-found-in-long-covid-patients-with-lingering-taste-loss-e9cb0508

A study published in *Chemical Senses* on January 29, 2026, revealed molecular and structural abnormalities in the taste buds of individuals experiencing persistent taste loss more than a year after recovering from COVID-19, linking reduced levels of a key protein to impaired detection of sweet, bitter, and umami tastes [2][4][9]. This research provides the first direct biological evidence connecting reported taste disturbances to measurable changes within taste receptor cells, offering new insights into a debilitating symptom of long COVID [2][4][7]. Understanding these mechanisms could inform future therapeutic approaches for those whose daily lives are affected by altered taste perception.

## What the Records Show
The study, led by teams from the University of Colorado Anschutz and several Swedish universities, focused on 28 non-hospitalized patients who reported taste disturbances over a year after contracting COVID-19 [4][6][7][8]. Researchers found a significant reduction in the messenger RNA (mRNA) encoding phospholipase C beta 2 (PLCβ2) [4][6][7][9]. PLCβ2 acts as a "molecular amplifier" inside taste cells, strengthening signals for sweet, bitter, and umami flavors before they reach the brain [1][4][6][7]. Reduced PLCβ2 levels can weaken these signals, making them too faint to register [1][6]. Microscopic examinations of taste bud tissue also showed structural disorganization in some participants, with abnormalities such as isolated PLCβ2-positive cells [1][3][4][5][9]. Taste cells for salty and sour flavors use different mechanisms not dependent on PLCβ2, which explains why these tastes often remain intact [1][4][6][7][10][11]. Viral RNA was not found in taste papilla biopsies, suggesting the long-term dysfunction is not due to persistent viral presence [3].

## The Timeline
The study, titled "Molecular and Structural Abnormalities in Taste Buds Linked to Persistent Taste Loss Post-COVID-19," was published in the journal *Chemical Senses* on January 29, 2026 [2][6][9]. The research involved patients who had experienced taste disturbances for more than one year after their initial COVID-19 infection [6][7][8].

## What Changed and for Whom
This research establishes a direct biological link between the subjective experience of long-term taste loss and specific cellular changes in the taste buds [2][4][7]. It moves beyond general viral disruption to pinpoint a molecular defect [3][4]. The findings indicate that long-term taste dysfunction after COVID-19 occurs in a subset of patients, more often affecting sweet, bitter, and umami tastes [4][5][9].

## What the Subject Has Said Publicly
Thomas Finger, PhD, a professor of cell and developmental biology at the University of Colorado Anschutz and a corresponding author of the study, described the protein's function [1][6][7]. Finger stated, "PLCβ2 acts like a molecular amplifier inside taste cells," and that it "strengthens the signal before it's transmitted to the brain" [1][6]. He also noted that "When levels are reduced, the taste signal weakens" [6].

## What We Could Not Confirm
The specific percentage of COVID-19 patients who develop this particular long-term taste dysfunction is not quantified in the available research [4][6][7]. While the study observed no viral RNA in the taste papilla biopsies of patients with persistent taste loss, the exact process by which the initial COVID-19 infection leads to the long-term reduction of PLCβ2 mRNA or structural disorganization, and whether these changes are reversible, was not detailed [3].

## Evidence cited
1. Scientists discover why some people still can’t taste food after COVID-19 (www.sciencedaily.com) — https://www.sciencedaily.com/releases/2026/10/261018205033.htm
2. Molecular and Structural Abnormalities in Taste Buds Linked to Persistent Taste Loss Post-COVID-19 (Chemical Senses) — https://example.com/url-not-provided-in-source
3. New Study Explores Why Some COVID-19 Patients Still Can't Taste (news-medical.net) — https://news-medical.net/
4. Why Some COVID Patients Lose Taste for Years - Neuroscience News (neurosciencenews.com) — https://neurosciencenews.com/
5. Taste dysfunction in long COVID - PMC (nih.gov) — https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11019623/
6. Scientists discover why some people still can’t taste food after COVID-19 (eurekalert.org) — https://www.eurekalert.org/news-releases/1036081
7. Breakthrough Study Reveals Biological Basis for Long-Term COVID-19-Related Taste Loss (bioengineer.org) — https://bioengineer.org/breakthrough-study-reveals-biological-basis-for-long-term-covid-19-related-taste-loss/
8. Long COVID Taste Loss Linked to Specific Molecular Changes in Taste Buds (pharmacytimes.com) — https://www.pharmacytimes.com/view/long-covid-taste-loss-linked-to-specific-molecular-changes-in-taste-buds
9. Taste dysfunction in long COVID (slu.se) — https://www.slu.se/globalassets/ew/org/andra-enh/kbh/nya-kbh/pdf/finger-et-al--2026--taste-dysfunction-in-long-covid--chemical-senses.pdf
10. A common signaling pathway for sweet, bitter, and umami taste. - PubMed (nih.gov) — https://pubmed.ncbi.nlm.nih.gov/12569148/
11. Taste Transduction Mechanisms for Sweet Umami Bitter Sour and Salty (bohrium.com) — https://bohrium.com/taste-transduction-mechanisms-for-sweet-umami-bitter-sour-and-salty/