Could seeding your home with a dose of beneficial bacteria keep you and your family in better health?
Although it may seem unlikely, it is an idea that is gaining ground among experts around the world.
The principle behind this is that just as our bodies have a microbiome (a community of bacteria, viruses and other tiny microbes), so do our homes, offices and even hospitals.
And just as maintaining a healthy balance of microbes in humans is key to keeping disease at bay, a healthy mix of microbes in our homes can “positively influence our health and well-being,” according to Sarah Haines, an assistant professor in the department. of civil affairs. and mineral engineering at the University of Toronto, and a contributor to a new book, Inside Out: Human Health And The Air-Conditioning Era.
Her research focuses on how buildings impact human health, with an emphasis on the indoor microbiome (she ventured into this field when her own grandmother developed respiratory problems and wanted to understand what effect her environment might have had on this).
The principle behind this is that just as our bodies have a microbiome (a community of bacteria, viruses and other tiny microbes), so do our homes, offices and even hospitals.
And Dr. Haines predicts that, just as people increasingly take probiotics in the hope that they can improve their health, in the future we will be able to “seed” our homes with probiotics (possibly in the form of materials with added bacteria) to change the microbiome there in order to “improve overall health.”
“We spend about 90 percent of our time indoors, so what happens in our homes and other buildings is critical to our health,” Dr. Haines told Good Health. “Ideally, the inner microbiome would be as balanced as the microbiome inside us.”
Some experts are working on ways to prime the materials used to build our homes with beneficial bacteria, an area known as “probiotic architecture.”
And researchers are working on ways to manipulate the microbiome within hospitals by using cleaning products that contain friendly bacteria, in the hopes that these “good” bugs will help keep the harmful ones at bay.
The idea that the environment inside our buildings can make us sick has been known for some time. In 1983, the World Health Organization first used the term “sick building syndrome” to define symptoms such as headaches, wheezing and watery eyes that were often attributed to poorly ventilated buildings and modern lighting.
But the internal microbiome (a newer, more radical concept) “is a developing area of science,” says Dr. Haines.
The composition of the microbiome within our homes is almost like a fingerprint “or a biosignature,” he says, in that it is unique to us and we begin to make our presence felt in the microbiome of our homes within hours.
In a study conducted by the University of Chicago, researchers asked seven families to clean themselves, as well as the light switches, floors, and countertops in their homes, and found that each home had a different microbiome.
What’s more, when three of the families moved houses during the six-week study, they altered the microbiome of their new homes within hours of moving, Science magazine reported in 2014.
The results showed how it is people’s microbes that have the greatest impact on an internal microbiome.
But other things influence it, such as if you have pets, who bring things from outside, as well as the level of humidity, ventilation and the way you clean your house.
A healthy mix of microbes in our homes can “positively influence our health and well-being,” according to Sarah Haines
Just as using antibiotics can kill good and bad bacteria inside our bodies, studies suggest that cleaning with bleach and other harsh detergents can alter a room’s microbiome by eliminating the good bugs that can keep the bad ones at bay.
During the Covid pandemic, researchers at the University of Ferrara, Italy, tried using a probiotic-based disinfectant instead of a chemical disinfectant in a children’s hospital for two months.
The goal was to see if this could keep it clean without disturbing the balance of the microbiome, since “hospital microbiomes can cause healthcare-associated infections” and the use of harsh detergents can “bring the threat of antimicrobial resistance,” they wrote. researchers in the magazine. Infections and drug resistance in 2022.
The cleaning product they used contained three strains of ‘probiotic’ Bacillus bacteria (B. subtilis, B. pumilus and B. megaterium), and the room and surfaces were cleaned twice a day as usual.
These surfaces were sampled at two, four and nine weeks: the results showed that there were 80 percent fewer pathogens (bacteria that cause infections) on the surfaces, and the insects that were present showed fewer signs of developing genes than those that were present. would make them resistant to standards. disinfectants.
In other words, the beneficial bacteria in the cleaning product helped prevent the cleaned surfaces from being reinfected with harmful bacteria.
The effects were reversed when the chemical disinfectant was reintroduced.
“If you use bleach, it kills everything, but when pathogenic bacteria land on the surface there is nothing that can compete with them and stop them from taking hold,” explains Mark Enright, professor of medical microbiology at Manchester Metropolitan University.
‘Bacteria produce compounds that can kill other types of bacteria. Therefore, introducing friendly bacteria to surfaces means that they all have to compete to survive.”
A previous study published in the journal Plos One in 2018 found that switching to a probiotic cleaning product nearly halved the number of hospital-acquired infections among patients in six hospital wards in Italy; While 4.8 percent of patients developed an infection before the 18-month study, that figure fell to 2.3 percent by the end of the study.
“I’ve moved a lot of plants into jars of water; if you go up and look at the soil, it can be covered in mold that you could inhale,” says Dr. Haines (file image)
However, there may be disadvantages, warns Jean-Yves Maillard, professor of pharmaceutical microbiology at Cardiff University. “One concern is that if bacteria enter the ventilation system and spread to an immunocompromised patient, these bacteria may not be so harmless after all.”
Meanwhile, some experts are researching how to design homes that are already primed with friendly insects.
Richard Beckett, associate professor of architecture at University College London, led a research project in 2019 that involved testing whether using concrete and ceramic tiles dosed with beneficial bacteria could reduce levels of pathogens such as MRSA within a building.
The study has not yet been published, but Professor Beckett says it appears to show some benefit.
He is working with a Finnish company to design materials that provide a probiotic boost to a building to help improve the health of its inhabitants.
And he’s using himself as a guinea pig for another study, starting next month, that involves mixing soil with ceramic tiles. ‘The soil comes from rural areas. The idea is that these samples contain microbes that are believed to be good for the immune system,” he says.
These “living tiles” will be used to cover your office. “Over the next few weeks, an immunologist will periodically draw my blood to see if there are any differences in my immune cells,” says Professor Beckett.
According to him, modern, sterile homes can increase the risk of diseases such as autoimmune diseases (e.g. type 1 diabetes).
“Since the 1960s we saw a decrease in infectious diseases due to the use of antibiotics, but also an increase in autoimmune diseases, and I think that is because our immune system is not exposed to microbes from a young age, so, instead of attacking the microbes, it starts attacking our body.’
Dr. Haines admits there’s a lot to learn: We still don’t know what the perfect home microbiome for health would be, “but we’re on the verge of understanding it.”
Your work is already shaping the way you maintain your home; For example, she “stays away from” carpets, “because fungi and bacteria will thrive in the warm, humid conditions there,” she says. “Then they get stuck in the carpet, and when you walk on it, you can kick it and inhale it.”
Nor do you grow houseplants in traditional soil pots anymore.
“I’ve moved a lot of plants into jars of water; if you get up close and look at the soil, it can be covered in mold that you could potentially breathe in.”
Meanwhile, Professor Maillard believes the best approach is “targeted hygiene.”
He explains: ‘There is evidence that excessive use of disinfectants contributes to antimicrobial resistance. Products used in homes typically have a low concentration, so when used only susceptible microbes are killed, while others survive without competition to suppress them.’
So instead, focus on areas where disinfectants might be a good idea from time to time, “like the bathroom or the kitchen sink, maybe once a week, like I do,” he says. . ‘And I use disinfectants for the surfaces where food is prepared.
“But many people use disinfectants on all surfaces and simply don’t need them; a damp cloth is fine.”
