In the most comprehensive study of its kind, researchers discovered that dust found in one’s home might improve asthma and allergies.

This seems counterintuitive, as most people have heard that dust makes allergy symptoms worse. However, the research team learned that dust actually enhances the immune system, making it more resilient. Researchers from the University of Copenhagen, along with the Danish Pediatric Asthma Center at Herley and Gentofte Hospital, took part in the study and published their findings in November of 2020.

The team discovered that microorganisms living in dust found in children’s beds correlated strongly with their own gut bacteria. The researchers believe the microorganisms may decrease the likelihood of a child developing asthma, allergies, and autoimmune diseases as they age. While we can’t see them, innumerable microbes share our beds with us, as they live in the dust naturally occurring in our homes. These microbes can influence the types and diversity of microorganisms that develop in our own bodies, especially in childhood.

The more diverse our gut bacteria, the more resources, and immunity our bodies have to fight off diseases. Therefore, children whose beds have more dust tend to have stronger immune systems. But, what causes certain microbes to settle in the dust of some homes and not in others?

The study

To better understand the relationship between dust and gut bacteria in children, the researchers took bed dust samples. They obtained these from 577 infant beds and compared them with samples of the respiratory system from 542 children. In the largest study of its kind, the researchers hoped to discover how environmental factors influenced the types of microbes found. Also, they wanted to see if the microorganisms found in bed dust affected the types of bacteria living in children’s airways.

“We see a correlation between the bacteria we find in bed dust and those we find in the children. While they are not the same bacteria, it is an interesting discovery that suggests that these bacteria affect each other. It may prove to have an impact on reducing asthma and allergy risks in later years,” explains Professor Søren J. Sørensen of UCPH’s Department of Biology.

The microbes living in our beds can boost our immune systems.

Of course, the more microbes which make their homes in our bed dust, the more resilient our immune systems become. Children need exposure to diverse bacteria to develop their immunity. Diverse microorganisms living in one’s home help to boost a child’s resistance to allergies and disease. Beds tend to collect an abundance of bacteria, fungi, and other microorganisms that cover their homes in dust.

“We are well aware that microorganisms living within us are important for our health regarding asthma and allergies, for example, but also human diseases such as diabetes II and obesity. But to get better at treating these diseases, we need to understand the processes by which microorganisms emerge during our earliest stages of life. And, it seems that the bed plays a role,” says Søren J. Sørensen.

Because our immune systems get stronger due to dust microorganisms, perhaps we shouldn’t wash our sheets quite as often. We live in an overly sterile, clean world, which actually lowers our immunity.

“Microorganisms in a bed are affected by a dwelling’s surroundings, where high bacterial diversity is beneficial. The simple message is that constantly changing bed sheets may not be necessary, but we need to investigate this a bit more closely before being able to say so for sure,” he added.

Rural living, pets, and older siblings boost gut bacteria.

The research team found 930 different types of bacteria and fungi in dust obtained from beds of six-month-old children. The homes’ environmental conditions and location greatly affected the diversity of bacteria found in the various samples. The team took samples from both urban and rural homes and found that rural dwellings had far higher bacteria levels.

“Previous studies inform us that city-dwellers have less diverse gut flora than people who live in more rural settings. This is typically attributed to their spending greater amounts of time outdoors and having more contact with nature. Our studies demonstrate that changes in bacterial flora in bed dust can be an important reason for this difference as well,” says Søren J. Sørensen

Previous studies have also found that rural living, pets, and older siblings help lower the risk of developing autoimmune diseases. As pets carry a diversity of fungi, dust, and soil in their fur, early childhood exposure helps boost immunity. Children need this exposure to germs and bacteria to bolster their immune systems and decrease disease risk. Our exploding urban population misses out on these important bacteria and have reduced gut diversity as a result.

Older siblings help younger children’s immune systems due to the mother having more active immune systems. Studies have found that infants whose mothers had been previously pregnant had more signal proteins, which triggered an immune response. This gets passed on to the younger sibling, which means their immune systems recognize threats, such as infection, more often.

In future studies, the research team hopes to find what types of bacteria in bed dust lead to allergies or asthma development.

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Final thoughts on the study about bed dust improving allergies and asthma

In a groundbreaking study, researchers have found that dust in children’s beds may protect them against allergies and asthma. In the Western world, especially, many people believe that dust causes aggravation of allergies. However, this study proves that our immune systems actually benefit from the presence of dust and bacteria in our homes. The study found that children with the strongest immune systems had more diverse microorganisms living in their bed dust.

Furthermore, the study discovered that children living in rural environments had more robust gut flora. This directly correlates to the types and diversity of microorganisms found in their homes. In future studies, researchers hope to determine if certain types of bacterial flora increase the chances of developing allergies and asthma.