Does it really work? Do sprays and mattress covers treated with probiotics actually remove dust mites?

We are certain that the mattress covers with probiotics have a beneficial effect on house dust mite allergy. The sprays are also promising, but still require clinical trials.

Each week we zoom in on a health claim and investigate if the claim is valid. This week: probiotics that supposedly chase away dust mites. "Originally, I was very skeptical," he says.

Nieuwsblad - Peter Van Dyck
Tuesday 26 September 2023 at 03:00
Original article:

"Removes 99 percent of dust mites"

"Makes you enjoy the night carefree"

"Makes odors disappear"

"100 percent natural, good bacteria"

These are claims circulating about sprays and mattress covers treated with probiotics. They are said to be a solution for people Who are struggling with a dust mite allergy. But is that really the case?

What is a house dust mite?

A microscopic spider that feeds on small dander from humans and animals. That's why it's so keen to settle in our bedrooms. In one bed, about two million dust mites can easily settle. House dust mites themselves are not dangerous to humans, but one in five Belgians is allergic to its feces. That allergy leads to sneezing, a runny nose, itchy or watery eyes and coughing.

And what are probiotics?

"It's a very broad collective term," explains Sarah Lebeer, microbiologist and bioengineer at the University of Antwerp. "According to the scientific definition, they are living microorganisms that, when deliberately administered in sufficient quantities, have a beneficial effect on human or animal health."

Probiotics are good, healthy bacteria that can strengthen the immune system and reduce the number of disease-causing bacteria. Especially in the diet they have become a real hype, because they can restore the intestinal flora.

"Europe is fairly strict on the use of probiotics, but for the time being regulations are limited to food, cosmetic products and medicines," says Lebeer. "If you want to use them in those areas, clinical research with patients involved have to prove that they are beneficial."

How could probiotics fight house dust mites?

According to Q-viva Probiotics, manufacturer of the 'Q-viva Allergen Spray', the probiotics digest multiple allergens, including the feces of the dust mite. They don't kill the critters, but they do scare them away. Sarah Lebeer calls the concept valuable. "There are indeed bacteria that can break down mites' feces and odors, two things known for leading to allergic reactions. As an academic, I do expect clinical trials to prove that the sprays and mattress covers effectively do what they promise."

Although the sprays are sold exclusively through pharmacies, they explicitly do not present themselves as medication, but as textile cleaners. This allows manufacturers to escape the obligation to carry out clinical studies and to release detailed information about the bacteria present in the products.

The Purotex mattress covers manufactured by BekaertDeslee do have such a clinical study. Philippe Gevaert, ear-nose-throat doctor at UZ Gent and specialized in allergies and immunotherapy, was involved. "BekaertDeslee had introduced the Purotex system, in which a mattress cover was impregnated with microcapsules containing probiotics. Due to the friction during sleep, the substances are systematically released. In a German lab it was proven that you could remove 90 percent of the dust mites with it, but does it also work in real life conditions? For the study, we gave patients struggling with house dust mite allergy two mattress covers: one with a placebo product and one with the probiotics. Originally, I was very skeptical, I honestly thought that the impregnated mattress covers would have little effect. To our great surprise, we saw that with the Purotex cover, after four weeks, the symptoms decreased and the quality of life of the patients, especially at night, increased."

The researchers are still in the dark about the exact way in which the probiotics work, professor Gevaert confesses. "It may be that probiotics reduce allergens, but it is also possible that the good bacteria act directly on your body and positively affect your immune system."

Are there any important differences between the sprays and the mattress covers?

The mattress covers are more practical to use. The scientists estimate that they maintain their effect for three to five years. The fact that they cannot be replaced quickly and have a relatively low cost in comparison to the sprays, which you have to apply on the textile every day, offers a more interesting business model for the producers.

The experts regret that the sprays don’t have clinical research with patients involved. They hope that the manufacturers will still initiate such studies. "If they can prove in a research paper that the sprays work, they could even obtain reimbursement from the health insurance funds," says Philippe Gevaert.

From feedback from patients, the ear-nose-throat doctor learned that, if they buy a spray, they often try it for a while, but then stop using it. "Maybe eventually it will be too much hassle for them to have to spray daily? We often see this difficulty in treatments where patients have to maintain certain actions. Keeping this in mind, the mattress covers have an advantage: once purchased, you don't have to worry about it anymore."

Do the microcapsules in the mattress covers not dissolve after multiple washes?

"Unlike sheets, the mattress covers are not put in the washing machine very often," counters Philippe Gevaert. "I'm afraid you will have some loss if you wash them a lot, but we don't have data on that."

Can the probiotics have side effects?

Philippe Gevaert did not encounter any side effects in his study. In 2008, physician-researchers at the University Medical Center Utrecht did identify clinical trials that described negative effects of probiotics on the respiratory tract.

"What applies in food applications, but also in those sprays and mattress covers, is that you demonstrate that the bacteria you're using are safe," says microbiologist and bioengineer Sarah Lebeer. "As scientists, we need to know the full DNA of the bacteria to be able to judge if it contains no toxic or bad genes. In the case of food products, even safe bacteria that do not cause harm in the intestines can cause irritation when inhaled. There should be tests with volunteers to check that the probiotics in sprays have no side effects. l can only hope that the companies behind these products follow up on any consumer complaints well and investigate thoroughly."


We are certain that the mattress covers with probiotics have a beneficial effect on house dust mite allergy. The sprays are also promising, but still require clinical trials.

So does it work as promised? RATHER YES.