How Your Building's Microbiome Shapes Your Health
The spaces we build are not sterile containers; they are living, breathing ecosystems that profoundly influence our well-being.
Look around you—the walls, the floor, the office desk. While they appear static, they teem with invisible life. An entire ecosystem of bacteria, viruses, and fungi coexists with us in our built environments, shaping our health in ways science is just beginning to understand. This hidden world, known as the "built environment microbiome," represents one of the most exciting frontiers where biology, architecture, and health science converge.
The built environment microbiome refers to the complex communities of microorganisms that inhabit human-constructed spaces—our homes, offices, schools, hospitals, and transportation systems 2 . These microbial ensembles are distinct from those in natural environments and are profoundly shaped by architectural design, ventilation systems, human traffic, cleaning practices, and even the materials used in construction 1 2 .
We spend approximately 90% of our lives indoors, making the indoor component of this microbiome particularly significant for human health 2 5 . Every hour, humans emit about 30 million microbial cells into their immediate vicinity, making us primary contributors to shaping these indoor microbial communities 8 . The buildings we inhabit, in turn, influence which microbes survive, thrive, or perish, creating a continuous feedback loop between humans and our built environments.
Historically, architectural approaches emphasized sterility and separation from the outdoor environment. Since the mid-20th century, buildings have been designed with what experts now call an "antibiotic" approach—featuring dry, enclosed indoor environments with limited outdoor ventilation and antimicrobial-treated surfaces .
Contemporary research suggests this approach has backfired. The depletion of microbial diversity in built environments has been linked to rising rates of chronic diseases including asthma, diabetes, heart disease, and immune disorders .
Traditional approach focusing on sterility, limited ventilation, and antimicrobial surfaces.
New approach promoting beneficial microbial exposure through natural elements and ventilation.
This understanding has sparked a revolutionary shift toward "microbiome-friendly architecture" that seeks to improve human health by exposing people to beneficial microbes rather than shielding them from all microbial contact . This new approach designs buildings with greater permeability to the outdoors, incorporating natural elements like plants and soil to promote microbial diversity indoors.
A groundbreaking study published in 2023 provided unprecedented insights into how microbial communities establish themselves in new buildings 9 . Researchers conducted a comprehensive 36-month longitudinal study tracking bacterial communities throughout the construction and commissioning of The OME, an experimental building in Newcastle upon Tyne, England.
The research team employed a meticulous sampling strategy:
The study revealed dramatic changes in microbial communities as the building transitioned from construction to occupancy:
| Metric | Before Commissioning | After Commissioning | Significance |
|---|---|---|---|
| Bacterial Richness | Higher | Significantly reduced | P < 0.001 |
| Community Structure | Similar to outdoor communities | Distinctly human-associated | R² = 0.14; P = 0.001 |
| Environmental Selection | 0.3% | 10.5% | 10.2% increase |
| Outdoor Influence on Indoor Communities | 17% | 0.004% | P = 2.04 × 10⁻¹⁵ |
The data revealed that human habitation fundamentally transformed the building's microbiome. Before commissioning, indoor bacterial communities closely resembled outdoor environments, dominated by soil-associated bacteria. After people began using the space, human-associated bacteria including Escherichia, Pseudomonas, and Klebsiella species became significantly enriched 9 .
| Bacterial Genus | Association | Pre-Commissioning Abundance | Post-Commissioning Abundance |
|---|---|---|---|
| Solirubacterales | Soil-associated | High | Low |
| Kaistobacter | Soil-associated | High | Low |
| Escherichia | Human-associated | Low | High |
| Pseudomonas | Human-associated | Low | High |
| Klebsiella | Human-associated | Low | High |
Perhaps most intriguingly, the study documented how human-specific building usage shaped microbial profiles in different rooms. Kitchens, bathrooms, and hallways each developed distinct microbial signatures based on their functions and cleaning regimens, demonstrating that how we use spaces determines which microbes thrive there 9 .
Researchers employ sophisticated tools to characterize these invisible communities:
| Tool Category | Specific Technologies | Function |
|---|---|---|
| Sampling Methods | Air impingement, condensation capture, surface swabbing | Collect microbial samples from various environments |
| Molecular Analysis | 16S rRNA sequencing, whole-genome sequencing | Identify microorganisms and assess diversity |
| Building Sensors | Temperature, humidity, CO₂, airflow sensors | Monitor environmental conditions affecting microbial growth |
| Bioinformatics | QIIME 2, phyloseq, ampvis2 | Analyze complex microbial community data |
Advanced sampling techniques include innovative approaches like aerosol condensation capture, which collects naturally occurring atmospheric water containing airborne microbes 8 . This method has proven highly efficient for capturing the "aerobiome"—the airborne microbial community we constantly interact with indoors.
Genomic tools allow scientists to move beyond merely identifying which microbes are present to understanding their functional capabilities—what these microorganisms are actually doing in their environment 5 6 . This is crucial for determining whether specific microbial communities contribute to health promotion or disease risk.
Collecting microbial samples from surfaces, air, and water
Genetic analysis to identify microbial communities
Bioinformatics tools to interpret complex data
The emerging understanding of built environment microbiomes points toward exciting possibilities for designing healthier spaces:
A new architectural philosophy that incorporates microbial considerations into building planning. This includes specifying materials that support beneficial microbes, designing ventilation systems that promote microbial diversity, and integrating natural elements into built environments 2 .
Between microbiologists, architects, building scientists, and public health experts is essential to translate research into practical applications. As noted in one interdisciplinary perspective, "Strengthening policies on microbial risk management, air quality, and sanitation in high-occupancy environments... will help create healthier, safer, and more resilient built environments" 2 .
Could eventually monitor and respond to microbial conditions in real-time, creating dynamic environments that optimize microbial exposures for health 2 . While this remains futuristic, current research lays the groundwork for such innovations.
Standard buildings with limited consideration for microbial health
Understanding how building design impacts microbial communities
Architecture that intentionally supports beneficial microbes
Buildings that actively monitor and optimize microbial environments
The built environment microbiome represents both a profound influence on human health and an unprecedented opportunity to design healthier futures. By recognizing that our buildings are living ecosystems that interact continuously with their human inhabitants, we can begin to imagine a new generation of probiotic architectures that work in harmony with microbial life.
As research advances, we're learning that the path to healthier humans lies not in creating sterile, microbe-free environments, but in cultivating diverse, beneficial microbial communities in the spaces where we spend our lives. The invisible world within our walls has much to teach us—if we're willing to listen.