A Bean-Based Chewing Gum Cut Oral HPV by Up to 93% in Lab Tests

A chewing gum made from beans dramatically reduced levels of human papillomavirus (HPV) in laboratory tests — an intriguing but very early step toward preventing the cancers HPV can cause.

Researchers at the University of Pennsylvania School of Dental Medicine, led by professor Henry Daniell, developed a gum from lablab beans, which naturally contain an antiviral protein called FRIL. Published August 4, 2026 in Scientific Reports.

What FRIL does

In tests on oral samples from patients with head and neck cancer, extracts from the gum reduced HPV by up to 93% in saliva and 80% in oral-rinse samples, with the FRIL protein appearing to trap the virus.

FRIL is a lectin — a protein that binds specific sugar structures. Plants produce lectins in quantity, generally as a defence against insects and pathogens, and their binding is highly selective for particular sugar arrangements.

Viruses are coated in sugars, and the pattern differs between virus types. A lectin recognising the arrangement on a given virus binds and cross-links particles into clumps — which is what trapping means here. Aggregated virus cannot reach or enter cells.

The mechanism is physical rather than biochemical: nothing is inhibited or destroyed, the virus is simply immobilised, which is why resistance is less likely to develop than against a drug targeting a viral enzyme.

Why HPV in the mouth matters

HPV is a leading cause of oropharyngeal cancer and other head and neck cancers, as well as cancers of the lip and oral cavity.

Oropharyngeal cancer has been rising in incidence in several countries, driven by HPV rather than by the tobacco and alcohol exposure that historically caused head and neck cancer. It affects a different population as a result — often younger, often non-smokers.

Unlike cervical cancer, there is no screening programme for it. Cervical HPV infection can be detected and precancerous change treated before cancer develops; oral HPV has no equivalent pathway, so tumours present as symptomatic disease.

A simple, low-cost way to lower oral HPV could in principle reduce that risk — addressing a gap that vaccination will eventually close for younger cohorts but not for adults already exposed.

Why a chewing gum

The delivery format is a considered choice rather than a novelty.

Reaching the mouth is straightforward; staying there is not. Rinses are cleared in minutes and saliva flow continuously dilutes anything applied. Chewing releases the active protein gradually over an extended period and distributes it across oral surfaces mechanically.

Producing the protein in a plant that can be processed into gum also avoids purification, which is the expensive step in protein manufacturing — relevant if the goal is a low-cost preventive for wide use.

The bacterial effect

The gum also nearly eliminated two harmful oral bacteria, Porphyromonas gingivalis and Fusobacterium nucleatum, and an engineered version adds an antimicrobial peptide called protegrin.

Both organisms are periodontal pathogens, and F. nucleatum has attracted separate attention in cancer research: it has been found within colorectal tumours and is associated with worse outcomes, though whether it contributes to cancer or merely colonises it remains unresolved.

The important caveat

This is an ex vivo study — it used patient samples in the lab, not living people, and there have been no human clinical trials.

The distinction is substantial. Adding an extract to a saliva sample in a tube is a controlled encounter at a known concentration. In a mouth, the protein must survive salivary enzymes, reach virus residing in tissue rather than floating in saliva, and act at whatever concentration chewing actually delivers.

Reducing virus detectable in saliva also is not the same as reducing infection. HPV causing cancer is integrated into the DNA of cells lining the throat, and virus in saliva is shed material rather than the reservoir.

What would come next

The researchers propose advancing the gum to clinical testing, either alongside current treatments or as a preventive measure.

Where vaccination leaves a gap

HPV vaccination is the established prevention, and understanding what it does not cover explains why an additional approach is being pursued at all.

The vaccine is prophylactic. It prevents infection by generating antibodies before exposure, and it does nothing about an infection already established — the immune response it produces cannot clear virus that has integrated into cells.

That leaves the adult population who were exposed before vaccination was available or offered. Coverage also remains uneven, particularly among boys, in countries where programmes began with girls on the reasoning that cervical cancer was the primary target — a decision that looks less well judged as HPV-driven throat cancer rises in men.

The generational effect is real and slow. Countries with high early coverage should see HPV-driven cancers fall substantially, and the benefit arrives decades after vaccination because these cancers develop slowly. For everyone already infected, something acting on existing virus would address a population the vaccine cannot reach.

A prevention trial is the harder one to run. It would require following people with oral HPV over years to see whether fewer develop cancer — expensive, slow, and requiring large numbers because the outcome is uncommon even among the infected. Until then, it remains a promising laboratory finding, not an available product. Research news, not medical advice.