“A nasal spray with postbiotics makes the immune system alert”


A nasal spray against viral infections that you can buy at a drugstore. It almost sounds too good to be true in this day and age when viral respiratory infections are in the spotlight. “People can then take control over how they deal with the virus,” says Prof. Dr. Hermelijn Smits, professor of mucosal immunity at the Leiden University Medical Center (LUMC). For the project for which she is requesting support through the LUMC Donation Investment Fund II, she collaborates with the Pulmonary Diseases department, the LUMC pharmacy and the Infectious Diseases department.

Mild to severe complaints

Viral respiratory infections are commonplace. The problem is that one person only gets mild cold symptoms, while the other ends up in the ICU and can even die. “The immune system reacts differently in people who become seriously ill from a virus,” Smits explains. “The production of substances in their body that clear viruses is probably disrupted. As a result, the first line of defense against a virus starts more slowly. You see this, for example, in people who have asthma or COPD or in people who are in hospital with serious corona.”

Bugs make postbiotics

Smits’ research focuses on the interaction of commensals with the immune system. Commensals are microscopic creatures that live on our skin, intestines or lungs, for example. These commensals can produce bioactive substances that put our immune system in mucous membranes (such as in the nose) into an alert state, so-called postbiotics. Smits and her team want to investigate whether a nasal spray with postbiotics can alert the immune system in the nose. Just as alert as healthy people who experience few or no cold symptoms after a viral infection.

Strengthen the mucous membrane in the nose

Smits explains why her research focuses on infections that enter through the nose. “Virus particles can settle in the nose through breathing. There they can infect local cells and boost the infection. You have probably used a nasal spray with saline solution for a blocked nose. You will then notice that the spray also ends up in the back of the throat. The idea is that the nasal spray with postbiotics against viral infections that we are developing strengthens the entire zone of mucous membranes in the nose and mouth.”

Testing postbiotics for rhinovirus

The hypothesis that ‘nasal spray with postbiotics protects against viral infections’ is initially tested on the rhinovirus. This virus causes mild cold symptoms in healthy people, just like corona, but vulnerable people can end up in hospital due to the virus. “We have experience in infecting people with the rhinovirus under controlled and safe conditions,” Smits explains this choice. “If it turns out that our approach reduces the symptoms of this virus, we want to test it for other viruses, such as flu and possibly even corona.”

Give a helping hand to the immune system

We have learned from corona that it takes quite a long time to make a virus vaccine. If you have to wait for a vaccine for every virus, it will come too late for many sick people. “Our own immune system is designed to defend us against viruses. Why not give that system a helping hand? The nasal spray that we want to develop is a preventive measure. Just as hay fever patients take a nasal spray during the hay fever season, people can take the nasal spray against viral infections during the flu season to get through the winter well.”

Nasal spray from pharmacy or drugstore

Smits and her team strive for a nasal spray that you can get from the pharmacy or drugstore, so that it is accessible to everyone. Then everyone can decide for themselves: I want to try this medicine to prevent serious respiratory infections. In this way you can reach a large audience and give people the power to do something about these problems. The elderly or people with asthma or COPD put themselves in a better defensive state with the nasal spray. We expect that vulnerable people will not become ill or will become less ill with, like other people, only mild complaints for a few days.”

The article is in Dutch

Tags: nasal spray postbiotics immune system alert


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