The 2025/26 flu season in the Northern Hemisphere is knocking on the door, and a surprising solution could change the way we test ourselves – instead of a nasal swab, it could potentially be enough to chew a piece of gum or slowly dissolve a lozenge in the mouth. Scientists have constructed a molecular sensor that, in the presence of the influenza virus, releases the aroma of thyme (the active component is thymol), which the tongue recognizes as a clear herbal note. The concept is designed as a fast, affordable, and low-tech method of home screening that specifically targets the virus's key "weak spot" – the enzyme neuraminidase – and thus opens the door for earlier detection of infections, including the period before symptoms appear when the sick are already contagious.

How the "tongue test" is supposed to work

The basis of the idea is simple: neuraminidase (the letter "N" in flu subtype designations like H1N1 or H3N2) is an enzyme on the surface of the influenza virus that participates in the spread of the virus through the respiratory epithelium. When the sensor, chemically adapted to mimic its natural substrate, comes into contact with neuraminidase in the oral cavity of an infected person, the enzyme breaks a specific bond and thereby releases thymol – the aromatic molecule responsible for the recognizable taste of thyme. This taste appears on the tongue as a "signal" that viral activity is present, without the need for an electronic reader or laboratory equipment. Relying on neuraminidase is logical because it is a well-studied target in both diagnostics and the development of vaccines and antiviral drugs, and its role in influenza biology is described in detail in literature and regulatory reviews.

From a laboratory idea to chewing gum and lozenges

The research team from Würzburg has developed a molecular "taste switch" that can be incorporated into gum or lozenge matrices. In laboratory experiments with saliva from individuals whose flu was confirmed by standard methods, the sensor released free thymol within 30 minutes – which the researchers recognized as a utility threshold for self-testing at home. The plan is to transfer the technology in the next phase into prototype chewing gums and lozenges and then evaluate it in clinical trials on humans, with an emphasis on the pre-symptomatic and early symptomatic stages. Patents describing this exact approach – a diagnostic sensor embedded in chewing gum for influenza detection via taste – are already publicly available and specify design solutions and its intended use for home application.

Why is this important right now

On October 2, 2025, many clinics and health centers are already in the preparation phase for the increased pressure of respiratory infections. The flu – just like other seasonal viruses – has an inconvenient characteristic: people become contagious before they develop symptoms. Standard PCR tests are very sensitive but more expensive and slower, while rapid antigen tests are practical but mostly "catch" infections after the virus has already reached a certain amount in the nose. The potential of the "taste on the tongue" is that it can detect virus activity in the oral cavity earlier, without taking a swab, without a reader, and without special sampling skills, which would increase the possibility of people staying at home at the first suspicion and thus reducing transmission in the family, school, or at work.

What exactly is thymol and is it safe for taste "signaling"

Thymol is a monoterpenoid phenol from the essential oil of thyme. It has a distinct herbal, warm taste that is easily recognizable, and it has been in use for decades in a range of consumer products – from mouthwashes to lozenges and other preparations. Its history and applications are well-documented in chemical and food references, and the fact that the sensory molecule is already well-known to consumers contributes to the idea that a "taste test" could be both practical and acceptable.

The critical target: neuraminidase

The influenza virus carries two main glycoproteins on its surface – hemagglutinin (HA) and neuraminidase (NA). While HA allows the virus to bind to host cells, NA "cuts" sialic acid linkages and helps newly formed viral particles to detach and spread. It is precisely because of this function that NA has proven to be a useful diagnostic target for decades: a series of studies and tests focus on its activity, whether through fluorescent, chemiluminescent, or other signaling approaches. The idea of a taste sensor fits into this logic – when NA does its cutting job, the taste compound is released and "informs" the user.

What do the early results say and when could we see the technology in application

In in vitro studies with saliva from patients with confirmed flu, the release of thymol within 30 minutes represented a clear taste signal. The next steps include a stepwise transfer to the clinical domain: development of stable formulations (chewing gum base, lozenges), standardization of sensor concentration, definition of the exact chewing/dissolving time and taste perception thresholds, and validation on a larger sample of participants in real-world conditions. Researchers estimate that the first clinical trials on humans could start in approximately two years, followed by regulatory steps.

What would home use look like

The envisioned scenario is intuitive: a person who has been in contact with the flu or is feeling the first, non-specific symptoms (mild cough, scratchy throat, fatigue) takes a chewing gum with the embedded sensor and chews it for a defined time (e.g., 10–15 minutes), or a lozenge that slowly dissolves. If the enzymatic activity of neuraminidase in the oral cavity is sufficiently pronounced, the taste of thyme should clearly appear. The advantage is that the user does not need to count or read anything – the tongue is the "detector." This shortens the time to a decision on self-isolation and further action (contacting a doctor, taking an official test if necessary).

Home tests for the flu: where is the line today

In recent seasons, several rapid home tests for influenza that work on the antigen principle have appeared, but availability, price, and sensitivity in the early stage are still challenges. Regulators are cautious with approving fully at-home solutions, and clinical performance often varies depending on the quality of sampling and viral load. Therefore, any approach that places detection "at the source" – the oral cavity and saliva, where some of the virus also replicates and is transmitted – is potentially useful as a first screening, even before the decision for classic testing.

Protecting the community: from schools to nursing homes

The greatest strength of such a sensor could be demonstrated in environments with increased risk: classrooms and kindergartens, homes for the elderly and infirm, hospitals and emergency services, large offices, and industrial plants. Simple, cheap, and fast self-testing before a shift, class, or entering a classroom can reduce the likelihood that a pre-symptomatically infected person unknowingly spreads the virus. The idea is not to replace medical diagnostics, but to move the decision for caution a few hours or days earlier than today – which makes a big difference in epidemiology.

What does science say about "taste" as a signal

In the field of biosensors, there has been a real boom in recent years: electronic tongues, fluorescent and chemiluminescent systems that detect neuraminidase for influenza detection, and various approaches to biochemically "translating" reactions into sensory signals have been developed. This new approach goes a step further because it uses the human sense of taste as its display – the most widespread "sensor" on the planet, which requires no batteries or apps. Previous research on NA probes and "taste" sensors confirms that the target enzyme is sufficiently specific and suitable for the rapid transformation of a chemical event into a readable signal.

Accuracy, false positives, and false negatives

As with any screening test, the key is the balance of sensitivity and specificity. The sensor's design, focused on neuraminidase, reduces the likelihood of interference with bacterial enzymes, and the choice of thymol as the signal molecule helps because it is a relatively specific and intense taste that few other compounds are commonly able to produce under the same conditions. However, validation on human volunteers will have to answer questions such as: what if a person consumes herbs or products with thyme immediately before the test, how much does the taste threshold differ among people, can mucosal inflammation affect perception, and how to calibrate the "silence" in the mouth after oral hygiene or eating. In this regard, the final protocol is expected to contain clear instructions (a pause from food/drink, chewing time, signal interpretation).

Safety and regulatory framework

Although it is a low-tech display of results, the sensor is high-tech in its chemical design. The safety assessment includes the biocompatibility of the carrier matrix (gum/lozenge), the toxicity of the signal molecule in the intended microdoses, and its stability during storage at room temperature. It will follow the path toward approval as an in vitro diagnostic medical device in the EU and potentially a procedure for emergency use authorization in other jurisdictions, which includes clinical confirmation of efficacy and accuracy, as well as oversight of the manufacturing process. Documented patent descriptions indicate that the technology is designed for precisely such a purpose, with clear definitions of construction and use.

The bigger picture: the oral cavity as a field for interventions

Within the scientific community, there is growing interest in oral interventions as a way to reduce the transmission of respiratory viruses: from antiviral chewing gums that physically or biochemically inactivate viruses to sensors that signal their presence earlier. Research published this year shows that certain chewing gum formulations can significantly lower the viral loads of several strains of influenza and herpes viruses in experimental models, confirming that the oral cavity is a relevant site for both prevention and earlier detection. The taste sensor fits into this trend as a passive "detector" that does not kill the virus but gives the user timely information.

Aroma as the "output screen": why thyme specifically

Thymol was chosen for the "screen" because it has an intense, recognizable profile and is stable in a range of consumer formulations. In addition to its sensory properties, thymol and related compounds from thyme are also pharmacologically interesting – antiviral, antibacterial, and antioxidant effects are recorded in in vitro systems, although these effects are not the primary goal of this sensor. It is critical that the dose in the sensor is microscopic and serves exclusively as a taste signal, not as a therapy. This offers clear, binary feedback that is simple for the user to interpret: the aroma has appeared – take precautionary measures.

Comparison with classic tests: where would the "taste test" fit in

In the current care algorithm, PCR tests remain the gold standard due to their sensitivity and specificity, and rapid antigen tests are used for quick decision-making, especially when the viral load is high. The taste sensor would be a screening step before both, especially in the pre-symptomatic phase when the virus in the nose may still be below the detection limit. A positive taste signal would likely prompt isolation and confirmation with one of the standard tests, while the absence of taste would generally mean that the person currently has no measurable NA activity in the mouth, with a recommendation to repeat the test the next day if symptoms progress.

Practical questions: price, supply, storage

One of the biggest advantages of the concept is the low production cost once the sensor design is standardized. Chewing gum and lozenge forms already have global supply chains, and the products can be stored at room temperature, which opens up the possibility of distribution in schools, pharmacies, offices, and households without a cold chain. It is also crucial that the non-electronic nature of the reading would eliminate the need for apps, batteries, and networking – it is enough to rely on human taste perception.

What existing patents and research tell us

Publicly available patent documentation already describes a diagnostic sensor that can be mixed into a chewing gum base for the purpose of detecting the influenza virus via taste. These documents state the logic of application at the first signs of a throat infection, with the expected benefit of an early decision on therapy and more rational use of antibiotics (which do not work on viruses). The patent records also track the identities of the inventors from the University of Würzburg, confirming the continuity of work from the laboratory to potential commercial applications.

From the lab to the classroom: application scenarios

• Morning screening in schools: students would chew a "test" gum before entering the classroom; the appearance of a taste means staying home and notifying parents.


• Employers and shift work: a quick screen before the start of a shift reduces the risk of "super-spreaders" in factories.


• Nursing homes: visitors chew a test before entering – a simple barrier to the virus entering among vulnerable individuals.


• Households: family members test themselves after exposure or the appearance of the first signs of weakness.

What will the clinical trial look like

To confirm its utility, prospective studies will be needed at the peak of the flu season. Participants would likely keep a symptom diary, perform the taste test at defined intervals, and simultaneously undergo PCR/antigen tests for comparison. The goal is to clarify: effectiveness in the pre-symptomatic period, the relationship between taste intensity and viral load, as well as specificity towards different influenza subtypes (e.g., H1N1, H3N2).

Precautions and communication with users

To avoid confusion, the packaging must clearly state that it is a screening tool, not a final laboratory diagnosis. The instructions should be formulated so that the user understands what to do after a positive taste (isolate, contact a doctor, possibly a confirmatory test) and what to do after a negative one (continue to monitor symptoms, repeat the test the next day, get vaccinated). This is in line with the approach that early behavior – staying home when you are potentially contagious – often makes the difference in the total number of secondary cases.

What if the "taste" is late – or comes too early

The biology of the virus is not uniform: some individuals will develop measurable NA activity in saliva earlier, some later. It is possible that the window period of the taste sensor will be earlier than that of a nasal antigen test, but also that there will be overlap in some infections. That is why proper serial testing (e.g., every morning after exposure) will be more important than a one-time test, and clear instructions on repetition will be an integral part of the product.

The role of vaccination and therapy

No screening tool replaces seasonal flu vaccination and timely antiviral therapy in high-risk patients. The "taste test" could serve as an early "trigger" for a conversation with a doctor, especially for the elderly and people with chronic diseases, for whom timely treatment is most important. In parallel, research on neuraminidase as a target that, along with hemagglutinin, contributes to the immune response and vaccine development continues – which further underscores the importance of this enzyme in strategies against the flu.

What to follow next

The coming months should bring stable prototypes and announcements about the design of clinical trials. It will be particularly interesting to see how the sensor behaves in the presence of different dietary habits and oral care, how the industry will solve the standardization of taste in relation to pH and the oral microbiome, and whether the technology can be adapted for other respiratory viruses that have unique enzymatic signatures.

Additional context: the evolution of neuraminidase detection

In recent years, various fluorescent and chemiluminescent assay systems for detecting NA activity have been developed – proof that the target is well-chosen and suitable for fast, sensitive tests. In this series, the "taste sensor" stands out because it eliminates the need for an instrument and maps the biochemical event directly to a human sense. This makes it a potentially most accessible screening tool – especially in situations where laboratories are not within reach or logistics are complex.

A useful reference for readers

For general information on the role of neuraminidase in influenza and on approaches to vaccines and inhibitors, readers can consult regulatory reviews and educational materials from relevant institutions. Additionally, for the curious, the history and properties of thymol as the compound that provides the "signal taste" are available in popular science articles from chemical societies. Please note: this information is supplementary and serves to better understand the scientific background of this technology.

At the beginning of October 2025, as we prepare for a new season of respiratory infections, the concept of a taste test brings an intriguing possibility: making the first step of diagnostics as simple as – chewing gum. How quickly and to what extent the idea of a "sensor on the tongue" will move from the lab to pharmacies will depend on the upcoming clinical trials, manufacturing solutions, and regulatory decisions.

Note for readers: This material is for informational purposes only and does not replace medical advice. If you suspect you have the flu, especially if you are in a high-risk group, contact your doctor and follow official recommendations for testing and treatment. For general information on the flu and vaccines, see materials from relevant public health institutions and current seasonal recommendations.