The Science of Competitive Exclusion
How beneficial bacteria claim space and food on the surfaces in your home, how that differs from chemical cleaning, and what published science says about the principle behind it.
By EnviroBiotics Science Team
Surfaces in nature are already taken.
Outdoors, soil, leaves and stones carry dense communities of microorganisms. Those communities grow out of constant competition, cooperation and balance among countless microbial species. Because the space is already taken, a newcomer finds little room and little food left over.
Ecologists call this principle competitive exclusion. It ranks among the most studied ideas in microbial ecology, and it sits at the center of how EnviroBiotics probiotics work on the surfaces in your home.
It also explains the gap between a probiotic approach and chemical sprays or air filters. A spray clears a surface and leaves it bare, while probiotics keep the space and the food on that surface occupied.
The principle
What Is Competitive Exclusion?
Competitive exclusion is a biological principle about two or more organisms competing for the same limited resources in the same environment. Ecologists formalized it as Gause's law, after the Russian biologist G.F. Gause's experiments in the 1930s. It holds that when resources run short, the species best adapted to use them will outcompete and displace the others.
In microbiology, the idea has a long history. In the early 20th century, the Nobel Prize-winning biologist Elie Metchnikoff proposed that lactic acid bacteria from fermented milk could crowd out other microbes in the gut. Researchers have since studied the same dynamic in many settings, from the human gut microbiome to poultry science, food production and the microbiology of buildings.
In practical terms, a microbe struggles to settle on a surface that other microbes have already claimed. Competition for food, space and nutrients is constant. The outcome depends on which organisms arrived first and which suit that particular environment best.
Published research
Decades of Published Research
Researchers have documented competitive exclusion across fields, from ecology to food science.
Poultry Science
Farmers who give chicks the gut bacteria of healthy adult hens as soon as they hatch offer a long-standing example of competitive exclusion: an occupied gut leaves little room for newcomers. Research published in Frontiers in Physiology (2022) found that the makeup of the bacterial community mattered. More diverse communities left less room for unwanted bacteria to take hold.
Food Spoilage Research
Research published in Applied and Environmental Microbiology identified competitive exclusion as a major way beneficial lactobacilli hold off spoilage yeasts and molds in fermented dairy. The lactobacilli scavenge the trace nutrients the fungi need to grow.
Soil and Plant Ecology
Bacillus is one of the most common groups of bacteria in soil and on plants, where it lives among countless other microbes competing for the same space and nutrients. EnviroBiotics' sister brand Agriotics makes probiotic products for agricultural settings.
Indoor Microbiome Research
Researchers writing in the Journal of Exposure Science (Nature) argued for viewing buildings as environments with their own microbial communities, worth understanding on their own terms, instead of as places to strip of microbes.
Microbiome science
Your Home Has a Microbiome Too
Your home carries its own community of microorganisms. The people and pets who live there shape it, along with ventilation, moisture and the materials in each room. Soft surfaces such as mattresses, sofas, rugs and curtains hold the largest share, because they collect the organic residue microbes feed on: dust, dander, shed skin and food traces.
In 2017 the National Academies of Sciences, Engineering, and Medicine published a major research agenda report titled "Microbiomes of the Built Environment." The report named dampness and mold among the most important indoor concerns. It also called for a fundamental shift in how scientists and building managers approach building microbiology: as an ecosystem rather than a surface to wipe.
The core idea
Occupied Space vs. Empty Space
Competitive exclusion turns on who uses the space and the food on a surface. On the soft surfaces in your home, the food is organic residue, and the bacteria that cause odor are among the organisms competing for it.
Beneficial bacteria that already occupy a surface and use its food leave odor-causing bacteria less room and less to live on.
The principle, applied to the surfaces where odor lives
Space
Probiotics settle on surfaces and take up room odor-causing bacteria would use
Food
They feed on the dust, dander, shed skin and food traces those bacteria depend on
Time
A steady supply keeps surfaces occupied as your household adds new residue each day
From lab to living room
How the Mechanism Works at Home
EnviroBiotics devices put the principle from the research above to work on the surfaces of your home.
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Dispersal and Surface Settlement
EnviroBiotics devices release natural probiotics, Bacillus strains found in soil and plants, as a fine mist. The probiotics settle on surfaces throughout the room, soft ones most of all: mattresses, bedding, sofas, rugs, carpets, curtains and pet beds.
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Feeding on Organic Residue
On those surfaces, the probiotics feed on the organic residue that builds up in any lived-in home: dust, dander, shed skin and food traces. Odor-causing bacteria depend on that same residue.
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Taking Up Space and Food
As the probiotics use that residue and occupy the surface, odor-causing bacteria find less room and less to feed on. You end up with fewer odor-causing bacteria on the surfaces where odor lives, and a fresher-smelling home.
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Allergens on Surfaces, Measured
In a 2024 controlled study, Indoor Biotechnologies (Cardiff, UK) applied the EnviroBiotics probiotic over 8 days and recorded a cumulative decrease in dust-mite, pet-dander and mold allergens, with a parallel simulation at EMSL Analytical (New Jersey). The study measured allergens on surfaces: an environmental result, not a medical one. See the research.
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Continuous Replenishment
The device keeps running, so new probiotics keep settling as fresh dust and residue build up. Allow about 2-3 weeks for the probiotics to settle across a room. A cartridge lasts up to about 90 days, and you use the system alongside your regular cleaning, not instead of it.
A different approach
Why Chemical Cleaning Works Differently
Chemical disinfectants kill microbes on contact, useful and unwanted alike. They have a real place in cleaning. Their effect wears off fast, though, and leaves an empty surface behind.
After a chemical wipe, a surface is unoccupied in biological terms. The wipe cleared away the microbes, useful or not, and the residue that feeds them starts building up again as soon as you use the room. No community holds the space.
The first microbes to arrive move in, with no established community to compete against, because the wipe removed that community too. Once the chemical's effect fades, you wipe again and start over.
Competitive exclusion runs in the opposite direction. EnviroBiotics keeps beneficial bacteria on the surface, holding the space and using the food there. That makes it a natural partner for your normal cleaning routine: you clean as usual, and the probiotics keep working on the soft surfaces you cannot wash each week.
Credentials
Certifications and Standards
EnviroBiotics uses natural Bacillus probiotics found in soil and plants. Its probiotic formula is MADE SAFE certified, its products are PTPA parent-tested, and EnviroBiotics makes them under an ISO 9001 quality system. Use as the label directs.
MADE SAFE Certified
PTPA Parent-Tested
ISO 9001 Quality System
EPA Reg. No. 94339-1
EnviroBiotics devices have no filters, add no fragrance and produce no ozone. They release probiotics that settle on surfaces and go to work where odor lives.
Frequently Asked Questions
What does competitive exclusion mean in simple terms?
It means beneficial bacteria occupy a surface and use up the food on it, so other bacteria find less room and less to live on. In your home, EnviroBiotics probiotics feed on the organic residue odor-causing bacteria depend on and take up the space those bacteria would use.
Is competitive exclusion established science or a new concept?
It is established science. Gause described the principle in his experiments in the 1930s, and Nobel laureate Elie Metchnikoff explored a microbial version of it in the gut in the early 20th century. Researchers have since studied it in ecology, poultry science, food science and the microbiology of buildings.
Is this the same as using a disinfectant?
No. Chemical disinfectants kill microbes without picking targets, and their effect fades, leaving an empty surface. Competitive exclusion works by occupying space and using up food. EnviroBiotics is not a disinfectant and does not replace cleaning; you use it alongside cleaning, on the surfaces where odor lives.
Does it reach surfaces I cannot wash every week?
Yes. A fine mist reaches them: the probiotics settle on soft surfaces that are hard to clean often, like mattresses, sofas, rugs, carpets, curtains and pet beds. For whole-building coverage through HVAC ductwork, see the E-Biotic Pro.
How long does it take to work?
Allow about 2-3 weeks for the probiotics to settle across a room. In its 2024 controlled study, Indoor Biotechnologies recorded a cumulative decrease in dust-mite, pet-dander and mold allergens on surfaces over 8 days. Read the research. You have 30 days from delivery to try it, with free returns.
Sources
References and Sources
These sources support the scientific background in this article, and you can open each one through its link.
- [1] Siedler S et al. (2020) Competitive Exclusion Is a Major Bioprotective Mechanism of Lactobacilli against Fungal Spoilage. Applied and Environmental Microbiology, ASM. Source
- [2] Meadow JF et al. (2019) Building upon current knowledge of indoor microbiology to construct the next era of theory. Journal of Exposure Science, Nature. Source
- [3] National Academies (2017) Microbiomes of the Built Environment: A Research Agenda. The National Academies Press. Source
- [4] EnviroBiotics research The 2024 Indoor Biotechnologies allergen study and EMSL Analytical simulation. Read the research
The Bottom Line
Competitive exclusion is a well-documented ecological principle with roots in research from the early 20th century. Scientists have studied it in fields from ecology and food science to the microbiology of buildings.
EnviroBiotics applies it to the surfaces of your home. Natural Bacillus probiotics settle on mattresses, sofas, rugs and curtains, feed on the organic residue odor-causing bacteria depend on and take up the space those bacteria would use. You get fewer odor-causing bacteria where odor lives and a fresher-smelling home. The BioLogic Mini covers up to 300 sq ft and the Biotica 800 up to 800 sq ft.
The EnviroBiotics Science Team reviewed this content. The published references above are public, and each one links to its source.