A stick of chewing gum has multiple uses. Some people use it as a quick fix for their breath, while others may use it for a sugar hit or purely out of habit. In one Penn lab, however, it has become something far more ambitious: a small, plant-based device designed to capture viruses in the mouth before they can spread. The idea starts with an uncomfortable fact. During an active infection, saliva can carry viral particles, and it spreads easily when people talk, cough, laugh, kiss, or share close air. If the viral load in the mouth drops, the chance of passing germs along could drop too. That is the scientific basis behind this antiviral chewing gum.
Penn Dental Medicine researchers have built gum tablets that release virus-binding proteins while someone chews. One version uses a plant-made ACE2 “decoy,” a target SARS-CoV-2 likes to latch onto. Another uses FRIL, a bean-derived protein that can bind sugar structures found on several viruses. In lab tests, the gum reduced detectable virus levels dramatically. The COVID-focused gum has also advanced into a Penn-led phase 1/2 clinical trial, moving the concept from bench science into human testing. It is an unusual approach, yet it tackles a familiar problem: stopping infections at the points where they spread fastest.
Why the mouth is a strategic place to intervene
People often imagine infection risk as something that comes only from the air. However, the droplets also land on others’ faces and can enter their mouths during close contact. Talking, coughing, and sneezing can transport saliva droplets at short range. A CDC occupational health document describes a typical route in direct language, stating, “droplets made when people with flu cough, sneeze, or talk land in the mouths or noses of people nearby.” That description fits many indoor situations, including clinics and shared homes. It also helps explain why dental settings carry extra concern during outbreaks, since the mouth is exposed during care.
Penn researchers also chose the mouth because it is easy to sample and measure. Saliva collection is simple, and PCR can quantify viral genetic material before and after chewing. In the 2025 Molecular Therapy paper indexed on PubMed, the authors framed their focus with a blunt comparison, noting that “Oral virus transmission is several orders of magnitude higher than nasal transmission.” That line is a rationale, not proof of prevention. It does not show gum stops infection. It shows why “debulking” the virus at a transmission site is attractive to test.
The COVID chewing gum and the ACE2 decoy concept
SARS-CoV-2 enters cells when its spike protein binds the human ACE2 receptor. The Penn approach uses that binding step as a trap. The Daniell lab produces an ACE2-based protein in plants, then incorporates plant material into gum tablets. Chewing releases the embedded protein into saliva, where it can bind virus particles. Penn’s clinical trial announcement summarizes the goal, stating that “The gum is designed to trap and neutralize SARS-CoV-2 in the saliva.” The intended effect is local, in the mouth, during and shortly after chewing. It is not described as a whole-body antiviral therapy.
The supporting evidence for this approach is preclinical. A Molecular Therapy paper led by Henry Daniell and colleagues is indexed on PubMed and describes a CTB-ACE2 chewing gum strategy. The study tested reductions in saliva viral load under experimental conditions, and it explored ACE2-related measurements. The PubMed record also includes a broad statement of intent, noting, “Chewing gum with virus-trapping proteins offers a general, affordable strategy to protect patients from most oral virus re-infections.” The keyword is “strategy.” It signals a concept that still needs clinical proof in people.
How Penn moved from lab assays to a phase 1/2 trial
A clinical trial changes the evidence standard because it tests use in real people. Penn’s 2022 updates describe a phase 1/2 study designed to measure safety and saliva viral load changes after chewing. The trial aims to enroll 40 participants and collect saliva over 3 days, followed by a clinic visit. Each participant provides multiple saliva samples, and the samples undergo PCR tests to quantify virus levels. This design can capture short-term shifts linked to chewing windows. It can also document side effects linked to repeated daily use.
The protocol is unusually specific about timing, which helps interpretation. Daniell describes the routine with a direct schedule, stating, “Each day participants will chew four tablets of gum, and take eight samples of saliva, before and after chewing.” Repeated sampling reduces guesswork about when any effect begins. It can show whether levels drop after chewing, then rebound later. It can also show whether the effect changes across days. This trial does not directly measure household transmission events. It is designed to first answer safety and saliva signal questions.
What “plant-based” means in this research, beyond branding
The “plant-based” label refers to how the active proteins are produced and packaged. Penn reports that the trial plant material is produced at Fraunhofer, then processed at Penn Dental Medicine. The workflow uses freeze-drying and grinding equipment that meets FDA-related requirements for the process. Plant production can reduce manufacturing costs because purification steps often add time and expense. Penn also emphasizes shelf stability and reduced reliance on cold storage in its 2022 reporting. Those distribution advantages matter for any product that aims for wide, global access.
Daniell frames the gum as part of a broader oral drug delivery platform. In the Penn Dental Medicine Journal PDF about the trial, he says, “I’m hoping that if this is effective and safe, it will be the beginning of several other oral delivery drugs using this platform.” That quote includes two gates: effectiveness and safety. It also signals that the team sees chewing gum as a delivery method, not a single-purpose product. The same PDF explains that the gum contains “plant-derived material genetically engineered to contain ACE2.” In other words, the plant material is the carrier for a functional protein, not just a flavor choice.
From a coronavirus decoy to a wider viral trap protein
An ACE2 decoy fits SARS-CoV-2 biology, yet it does not address viruses that attach in other ways. To broaden the approach, the Penn team explored FRIL, a protein found naturally in Lablab purpureus, also called the lablab or hyacinth bean. FRIL binds certain glycan structures that can appear on viral surface proteins. Penn Dental Medicine describes the key idea, noting that “FRIL binds to molecules called complex-type N-glycans, which are found on a broader spectrum of viruses.” That binding could encourage viral clumping or trapping in saliva, reducing free virus during chewing.
The 2022 Penn Dental Medicine update also explains how the team tested gum performance in vitro. It describes 2 assay platforms used to evaluate gum function, including microbubbling and electrochemical sensing approaches developed at Penn. The report also describes collaborations with Penn Medicine experts who helped collect COVID-positive samples and determine viral strains. Those partnerships support testing in real patient materials, not only in lab-prepared solutions. Still, in vitro assays cannot fully replicate a human mouth. Saliva chemistry, chewing behavior, and timing vary widely by person. That is why clinical studies remain essential.
What the flu and herpes results show, and what they do not
In March 2025, Penn Today reported results from a Molecular Therapy study led by Penn Dental Medicine researchers with collaborators in Finland. The team tested a chewing gum made from lablab beans that naturally contain FRIL. They evaluated 2 influenza A strains and 2 herpes simplex viruses in experimental models. Penn Today highlights a dose threshold, stating, “40 milligrams of a two-gram bean gum tablet was adequate to reduce viral loads by more than 95%.” That result is promising, yet it is still a controlled experimental finding. It does not show reduced outbreaks in a community setting.
The disease context for herpes helps explain why researchers pursue tools that act in the mouth. WHO estimates a very large global burden of HSV infections. A 2025 WHO fact sheet states, “An estimated 3.8 billion people under age 50 (64%) globally have herpes simplex virus type 1 (HSV-1) infection.” The same fact sheet reports, “An estimated 520 million people aged 15–49 (13%) worldwide have herpes simplex virus type 2 (HSV-2) infection.” These numbers show why simple, portable interventions are attractive to test. Still, the gum results do not prove that chewing prevents infection or stops recurrence. They show viral reductions under experimental conditions that need human validation.
Durability, dosing, and the meaning of “clinical-grade” gum
A key barrier for protein-based products is stability, especially in warm environments. Proteins can degrade in heat and humidity, which can shorten shelf life. The 2025 Molecular Therapy work emphasizes unusually long stability at ambient temperature. In the PubMed abstract, the authors write, “FRIL is highly stable in the lablab bean powder (683 days) and in chewing gum (790 days).” Long stability can make trials easier, since products can ship and store without complex cold logistics. The abstract also describes chewing simulation work, including substantial FRIL release within 15 minutes. These details support feasibility, yet they do not replace clinical outcome data.
“Clinical-grade” is a statement about manufacturing and contamination control, not about proven clinical benefit. The PubMed record reports bioburden testing results, including “no aerobic bacteria” and “no yeasts/molds,” along with low moisture content. It also reports no detectable levels of certain glycosides, which supports safety screening claims. Penn’s Institute for Immunology and Immune Health repeats that the researchers prepared the gum to comply with FDA specifications for drug products and found it to be safe. The team’s conclusion remains forward-looking, not final. Daniell says, “These observations augur well for evaluating bean gum in human clinical studies to minimize virus infection/transmission.”
Read More: Doctors Warn of Rare Post-COVID Syndrome That Can Be Fatal
What to watch for next, and where chewing gum could fit
The key question is whether laboratory effects translate into effects in people. For the COVID chewing gum, Penn’s reports describe a phase 1/2 trial with intensive saliva sampling and clinical monitoring. Results from such a trial can show whether chewing reduces saliva viral levels and for how long. It can also reveal side effects tied to repeated exposure to the gum tablets. For influenza and herpes, the strongest evidence remains in experimental models and lab assays. Human studies would need endpoints that track real-world use, including timing, adherence, and meaningful clinical outcomes. Those trials would also need careful messaging, since “lower viral load in saliva” is not the same as “no infection risk.”
Access is a stated aim of the Penn effort, especially for products that do not rely on refrigeration. Penn Center for Innovation quotes Michael Poisel saying, “One of the exciting things about the technology is the potential to help people in countries that don’t have the resources.” That goal depends on evidence, approvals, and manufacturing scale. It also depends on clear labeling and careful claims, so people do not treat gum as a stand-alone shield. Even if a gum reduces the saliva viral load, it would still be one layer in prevention. It would complement other measures that reduce exposure and severe disease risk. The science so far supports continued testing, with human data as the next decisive step.
The Bottom Line
Plant-based antiviral chewing gum has shifted from concept to clinical evaluation. Penn Dental Medicine engineered gum that releases virus-binding proteins into saliva. Their stated aim is clear, saying, “the gum is designed to trap and neutralize SARS-CoV-2 in the saliva.” Lab assays and simulated chewing tests suggest sharp reductions in detectable virus. Those signals still need confirmation from diverse participants under everyday use. Saliva viral load can drop quickly, yet levels can rebound between chews. Clinical sampling across 3 days should clarify timing, dose, and variability. It also tests whether chewing changes live virus levels, not just fragments measured by PCR in saliva.
Next studies must show tolerability and how long any reductions persist after chewing. Researchers also need endpoints linked to real transmission, not only PCR counts. Trials should report variant coverage, adherence, and interactions with food, drinks, and oral hygiene. If benefits hold, gum could help clinics and households during seasonal outbreaks. It would complement vaccination and cleaner indoor air, especially in crowded rooms. It could support people who cannot isolate easily. If benefits fall short, the work still advances oral delivery and plant-made proteins. Clear labeling and public guidance will prevent overconfidence and keep expectations aligned with evidence.
A.I. Disclaimer: This article was created with AI assistance and edited by a human for accuracy and clarity.
Read More: Did a Record Flu Season ‘Hold Back’ COVID-19 This Winter?