An experimental chewing gum can reduce the spread of Sars-CoV-2, the virus that causes COVID-19, according to a recent study published in the journal Molecular Therapy. You may have already noticed headlines calling the results “fresh hope” in our fight against COVID-19. But how excited are we to be? And could this chewing gum work against Omicron, the latest variant of concern?
Evidence shows that people infected with Sars-CoV-2 have high levels of virus in their saliva. So researchers in the United States wanted to investigate whether a specially designed chewing gum could reduce the amount of virus in the mouth and therefore potentially reduce its spread.
Chewing gum to promote oral health is not a new idea. Studies have shown that chewing gum containing certain substances such as calcium and bicarbonate can improve oral health, reduce the incidence of dental disease and reduce the number of harmful bacteria. But specifically targeting a virus in this way is a new approach.
Sars-CoV-2 gains access to human cells by locking on to ACE2 proteins, which are found on the surface of certain cells in our body. The researchers produced a chewing gum that contained high levels of ACE2 proteins, produced in plants, with the idea that the ACE2 proteins in the chewing gum could “capture” virus particles in the mouth, minimizing the possibility that they have to infect our cells and spread to other people.
To test the effectiveness of the chewing gum, the researchers took saliva samples from patients with COVID-19 and mixed these samples with a powdered form of the chewing gum. They found that the treated saliva had significantly reduced the number of Sars-CoV-2 virus particles compared to those treated with placebo (the same chewing gum but without the ACE2 protein).
The researchers also showed that the chewing gum prevented a pseudotype virus (a harmless virus with the Sars-CoV-2 tip protein on the surface) from infecting cells in the laboratory. As little as 5 mg of the chewing gum was associated with significantly reduced viral penetration into cells, while 50 mg of the chewing gum reduced viral penetration by 95%. This suggests that the ACE2 chewing gum severely impedes the ability of the Sars-CoV-2 tip protein to infect cells.
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Reasons for caution
While these results seem promising, there are a number of reasons why we may not see this chewing gum as a pandemic game changer yet. First, this is research in the early stages, which means that the experiments were performed in a laboratory under controlled conditions instead of with real people.
The conditions in a laboratory experiment will be different from the conditions in a person’s mouth. While the researchers used a chewing simulator to show that the chewing movement does not affect the integrity of the ACE2 protein in the chewing gum, there are other questions that we do not yet have answers to.
For example, would the environment in a person’s mouth, such as body temperature and oral bacteria, affect the effectiveness of the chewing gum? And how long would a piece of chewing gum continue to work? It will be interesting to see if the chewing gum has similar effects in humans as it has in the laboratory if research progresses to this stage.
Second, although the chewing gum significantly reduced the infection of a virus carrying the Sars-CoV-2 tip, the researchers did not use the full Sars-CoV-2 virus in their experiments. While the method they used, virus pseudotyping, is a proven scientific method for assessing virus penetration into cells, it would be interesting to see how the chewing gum affects the full Sars-CoV-2 virus.
As to whether the chewing gum would be effective across different COVID variants, such as Omicron, the principles of virology give us reason to be optimistic. Regardless of the variant and its mutations, Sars-CoV-2 gains access to human cells by locking in to ACE2 proteins – which is the key to how the chewing gum works. That said, this is another question that we do not know for sure the answer to until the product has been tested in real trials.
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Finally, it is important to understand what this chewing gum is designed for. The researchers point out that its main use is likely to be to reduce viral spread from people with COVID-19 to others, especially in clinical settings. It is unclear how well it would work as a prophylactic to prevent uninfected people from getting the virus, especially when Sars-CoV-2 can be transmitted through several pathways, including the eyes and nose and mouth.
Still, this chewing gum could have exciting prospects in clinical settings – for example, by reducing the spread in dental surgeries or COVID hospital wards. When used in combination with current methods such as masking, ventilation and vaccination, it can be another weapon in our arsenal to prevent the spread of COVID-19. But further research is needed before we can expect to chew it.