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Do HypoAir products kill the “good” bacteria as well as “bad” bacteria?

Short answer: yes, some good bacteria are killed, but let us explain a little about the nature of bacteria, and how this technology affects them!

Since HypoAir’s bipolar ionization is made for the home, we are talking about “good” bacteria for humans, found on exposed home surfaces, the skin, and upper respiratory tract, because this type of ionization does not penetrate to interior surfaces.

So the answer is: yes, bipolar ionization does kill some “good” bacteria, but the type of bacteria, on which surfaces, at what humidity, at what concentration of ions, and so on, are highly variable!   We find that the biological and air quality contaminants found in homes are typically in high unhealthy concentrations, which are typically not found in the outside air.   We want to reintroduce natural counterbalances to suppress the spread and growth of these biologicals indoors, to make them more similar to what's found in nature.  However, our technologies are not going to sterilize the environment; they're just designed to cut concentrations and reduce illness in families.  In 20-30 years, technologies like ours could become very cost effective and installed throughout a home to have a nearly sterilizing effect in our indoor environments.  We don't want that!  At that point, the intentional reintroduction of a positive biome would be advisable.  If you are concerned that the use of bipolar kills too many good bacteria, you may want to investigate probiotics for the air to replace those good bacteria on surfaces, and use gentle cleansers and soap for your skin, dispensed from containers that don’t promote the growth of bacteria.  And, consider the fact that pets (and dogs especially) vary the nature of your home’s microbiota a lot too!  

Getting back to bacteria, here’s a short refresher from an article about bacteria, endotoxins and exotoxins:  bacteria can be classed into two different groups: “Gram-negative” or “Gram-positive”.  These classes are based on a test developed by scientist Christian Gram in 1884, which differentiates the bacteria using a purple stain.   According to webmd.com, bacteria either have a hard, outer shell, or a thick, mesh-like membrane called peptidoglycan.  The hard outer shell will resist the purple stain, and show up as a red color.  These are called “gram negative” because the purple stain did not show.  Bacteria with the peptidoglycan absorb the purple stain much more easily and are called “gram positive”.  The stain also tells many more characteristics about the bacteria and the way it interacts with bipolar ions.

Bipolar technology is also called cold atmospheric-pressure plasma (CAP), or non-thermal plasma (NTP).  In a study which analyzed how plasma affected bacteria in soil, it turned out that the non-treated soil consisted of both gram-positive and gram-negative bacteria from different phyla (a level of classification).  After treatment with plasma, however, the gram-negative bacteria were mainly eradicated, and only the major phyla of Firmicutes (gram-positive) were left.  Presumably this has to do with the structure of the bacteria.

The authors cited two previous studies on treatment of E. Coli (gram-negative) and S. Aureus (gram-positive) with cold plasma.  In the first study, the treated Gram-positive bacteria was mainly inactivated by intracellular damage, while the Gram-negative bacteria expired mainly by cell leakage.  The second study showed that plasma treatment led to damage of the bacterial cell wall of both E. coli and S. aureus and a decrease in the total concentrations of nucleic acid and cellular protein. However, S. aureus (gram positive) was less susceptible to plasma exposure in comparison to E. coli (gram-negative).

The sum of these three studies seem to indicate that gram-positive and gram-negative bacteria are affected by plasma differently, and chances of survival of bacteria after treatment with cold plasma is higher if a bacteria is gram-positive, having more of the mesh-like membrane (peptidoglycan).  One can see from the diagrams below that these peptidoglycan layers are relatively thick on the gram-positive type, which may account for its resistance to plasma.  Depending on the relative humidity of the air, plasma can form varying quantities of reactive oxygen species such as hydroxide ions (OH-), hydroxyl radicals (•OH), atomic oxygen (O), hydrogen peroxide (H2O2), and singlet oxygen (1O2).   Ozone (O3) is another ROS formed by plasma generators, however we’ve excluded it from HypoAir ionizers by limiting the input energy.  These ROS are reported to damage the bacterial structure and functions.  In addition, the multiple reactive nitrogen species (RNS), including nitric oxide (NO), peroxinitrites (ONOO−), nitrites (NO2−), and nitrates (NO3−), can play a major role in the plasma’s biocidal process by altering the cell wall components, the functions and the structure of the phospholipid bilayer, the structure of nucleic acids and cellular proteins, gene expressions, and protein synthesis. (Effects of Atmospheric Plasma Corona Discharges on Soil Bacteria Viability)

Image source: Difference between gram-positive and gram-negative cell wall

However, there are factors other than gram-type that affect bacterial eradication via plasma technology, such as pH, humidity, and the surface on which the bacteria were placed during plasma exposure.  Specifically, 

• Lower pH can translate to higher kill rates.  A reduction of 4.9 log was observed when Bacillus cereus was treated at pH 5, while a reduction of only 2.1 log was observed at pH 7.  Interestingly, the same study showed that “No appreciable differences between gram-positive and gram-negative pathogens were observed, although the spore-forming B. cereus was more resistant to plasma than non-spore-formers.” (Spores in bacteria are not the same as mold spores; only one bacteria makes one spore). 
• Humidity was also reported as an important parameter; increasing the relative humidity was correlated to efficiency in plasma inactivation of Aspergillus niger, which was explained by the generation of more hydroxyl radicals. However, the same study showed that “In contrast, B. subtilis showed slightly poorer inactivation at high gas humidity.”
• Regarding the surface on which the bacteria were placed during plasma treatment, higher eradication was observed when microorganisms were loaded on a filter compared to a fruit surface, because the microbes could “migrate” to the interior of the fruit.  Therefore, if the bacteria could migrate into a moist surface, it was more likely to survive. (Cold Atmospheric Plasma Disinfection of Cut Fruit Surfaces Contaminated with Migrating Microorganisms)  Wow, bacteria can migrate! 

Now that we know that there are a lot of variables in your home that affect the mortality of bacteria, how likely is it that “good” bacteria on skin, your upper respiratory system, and home surfaces will be killed?

First of all, let’s look at what types of bacteria these are.  Staphylococcus epidermidis (phylum Firmicutes, gram-positive)  is a part of the skin microbiota (aka skin flora) and another type of good bacteria is Roseomonas mucosa (phylum pseudomona dota, gram-negative), which is naturally present on the skin and contributes to an overall healthy skin microbiome. (Dermatologists Break Down the Difference Between Good and Bad Bacteria)  In addition, the optimal pH value of skin on most of our face and body lies between 4.7 and 5.75, which is mildly acidic. (Understanding skin – Skin’s pH)  According to the studies above, it’s not known whether good bacteria on healthy skin survive plasma treatment, because although healthy skin is normally mildly acidic (which promotes their death by ions), moist skin favors preservation of good bacteria. Therefore, no matter what relative humidity is in your home, it’s a good idea to keep your skin hydrated!  

Concerning the upper-respiratory tract, potential keystone microbiota are Dolosigranulum and Corynebacterium species (both gram-positive), as they have been strongly associated with respiratory health and the exclusion of potential pathogens, most notably Streptococcus pneumoniae, in several epidemiological and mechanistic studies. (The microbiota of the respiratory tract: gatekeeper to respiratory health)  Regarding pH, airway surface liquid pH in normal airways ranges in vivo between 5.6 and 6.7 in the nasal mucosa, and is around 7.0 in bronchia.  (Airway Surface Liquid pH Regulation in Airway Epithelium Current Understandings and Gaps in Knowledge) Therefore it’s mildly acidic in the upper regions, and tending toward neutral pH in the lower regions.  Being gram-positive favors survival, as does being in mucous, but being on a mildly acidic surface favors eradication of these good bacteria.  Again, keeping your mucous membranes moist via water intake and plain saline sprays is a good idea!

Finally, most of the ions that are emitted by bipolar devices will contact surfaces in our homes.  What kind of good bacteria live on surfaces?  Forty homes in North Carolina were sampled for a study in August 2011.  Standard places like cutting boards, kitchen counters, door handles, toilet seats and pillowcases were sampled.  The bacterial families with the highest relative abundances across all of the collected samples were the Streptococcaceae (8.9%) (gram-positive), Corynebacteriaceae (5.6%) (gram-positive), and Lactobacillaceae (5.1%) (gram-positive).  Since these are all gram-positive, their survival would also depend upon the acidity and nature of the surface.  Keeping the humidity in the home in the sweet range of 40-60% will favor the production of more bacteria-killing hydroxyl radicals, and cleaning regularly is important.  Wet, dusty or cluttered surfaces will actually promote good bacteria survival, but they also promote bad bacteria survival too, so to play it safe, it’s best to keep surfaces clean!  

BALOs: voracious good bacteria

Bacteria in general have bad connotations: infection and illness to name a few.  But increasing awareness about the benefits of probiotics and natural gut bacteria have taught us that not all bacteria are bad: there are good bacteria too.  Bdellovibrio is in the good bacteria category and recent discoveries about it are spurring more possible uses.

Bdellovibrio bacteriovorus, which was first discovered in 1962, is a gram-negative, aerobic bacteria, which means it has a hard, outer shell that resists the purple stain used to differentiate strains of bacteria.  (For more information on gram negative and gram positive bacteria, check out our post here.)

Bdellovibrio is also a predator.  It is capable of killing and replicating inside over 100 different types of Gram-negative bacteria, including antibiotic-resistant pathogens, giving it a reputation of being a “living antibiotic”.  These prey bacteria include such well-known pathogens as Escherichia coli, Helicobacter pylori, Klebsiella pneumoniae, Pseudomonas, and Salmonella.  This predation behavior has even spawned a new acronym for this type of bacteria: Bdellovibrio and Like Organisms, or BALOs.

According to the following analysis, Bdellovibrio sounds like a voracious alien by attaching to, penetrating, and killing host bacteria, then using them to incubate its own progeny:  “In the wild, B. bacteriovorus uses chemotaxis and a single polar flagellum to hunt groups of prey bacteria. Once in close proximity, B. bacteriovorus collides with individual prey and attaches through an unknown mechanism. Next, B. bacteriovorus invades the prey periplasm (layers around the cell), likely through use of retractable pili, and secretes hydrolytic enzymes that kill the prey within 10 to 20 min of invasion. The predator subsequently remodels host peptidoglycan to form the spherical bdelloplast, where it degrades intracellular contents to fuel its own filamentous growth (liquidates the insides of the prey to fuel replication). Finally, 3 to 4 h following initial contact, the prey cell is lysed (ruptured), and four to six daughter cells emerge from their protected niche (the bdellovibrio babies emerge). Wow!   

Bdellovibrio is found naturally in soil and water, including rivers, lakes, the open ocean, and sewage and wastewater treatment plants (WWTPs).  They are also found in the gills of certain aquatic animals like crabs and oysters, and some mammal intestines.  

Here are some of the proposed uses of BALOs:

• It could be used in a probiotic to foster healthy human gut microbiota (Higher Prevalence and Abundance of Bdellovibrio bacteriovorus in the Human Gut of Healthy Subjects)

• It could be an effective treatment for pneumonia in lungs, as both B. bacteriovorus and M. aeruginosavorus could reduce the burden of K. pneumoniae in rat lungs, and B. bacteriovorus treatment is also effective in Yersinia pestis infection of mouse lungs. However, it was found that B. bacteriovorus and M. aeruginosavorus did not reduce pathogenic colonies in the blood, as it did in the lungs of these animals.  (Predatory Bacteria Attenuate Klebsiella pneumoniae Burden in Rat Lungs, Susceptibility of Virulent Yersinia pestis Bacteria to Predator Bacteria in the Lungs of Mice)

• It could be an effective treatment for Cystic Fibrosis (CF), in which patients have a defective gene that hampers immune response and causes them to be prone to chronic lung infections with an exaggerated inflammatory response.  In CF patients, instead of a diversity of microbiota, only two pathogenic microbes prevail, namely usually the Gram-negative P. aeruginosa and the Gram-positive S. aureus.  Therefore Bdellovibrio was used in a 2014 study to “challenge” these 2 strains in a lab setting, and it was able to reduce the biofilm of both cultures dramatically, even in “flow” settings.  The scientists were even able to photograph (at 30-50 times magnification) Bdellovibrio preying on S. aureus bacteria (see photo below).

Source: Study: Bdellovibrio bacteriovorus directly attacks Pseudomonas aeruginosa and Staphylococcus aureus Cystic fibrosis isolates

• Prolong food storage:  This study proposes that Bdellovibrio could be used to prolong the shelf life and reduce additives to packaged meat, because it was tested on chicken slices and canned beef and found to reduce colonies of E.Coli by 4.3 log and 2.1 log respectively.  The Bdellovibrio was able to lyse (rupture) all the strains of E. Coli that were tested.  In a separate investigation of Bdellovibrio and E. Coli, this video shows how an actual Bdellovibrio cell multiplies inside an E.Coli cell and destroys it from the inside out.

• It’s already been recognized as a mode of controlling bacteria in water supply systems.  In 2020 in Varberg, Sweden, a municipal water supply company decided to replace its chlorination system with ultrafiltration, which is an ultrafine mesh filter that prevents microbes from passing through.  Scientists monitored the results closely following discontinuation of chlorine, and some bacteria grew, but then decreased drastically.  By the third month, Bdellovibrio had flourished and harmful bacteria had diminished.  This showed that chlorine had actually suppressed the natural predatory action of bdellovibrio in the biofilm on the inside of drinking water distribution pipes where the good and bad bacteria live. (Predatory bacteria could be used to purify water in the future, study suggests)

So, what’s keeping us from using BALOS as natural antibiotics?  Of course, scientists want to make sure that there will be no harm to humans.  A number of studies using the two BALOs B. bacteriovorus and M. aeruginosavorus “demonstrate their inability to invade mammalian cells, and no apparent pathological effects or signs of cytotoxicity or reduction in cell viability, supporting the proposition that these two BALOs are inherently non-pathogenic to mammals.” (Biotechnological Potential of Bdellovibrio and Like Organisms and Their Secreted Enzymes)  However, scientists are also concerned that prey bacteria could become resistant to it, if it incompletely eradicates the prey. 

In addition, varying amounts of oxygen are necessary for BALOs to work on their prey.  Finally, in complex microbial environments like in our bodies or even in a wastewater treatment plant, it’s not always easy to predict how introduced BALOs will change the biome or which microbes they will prey on, although some do have preferred prey.  Certain chemicals also reduce their effectiveness.

In conclusion, it’s amazing what goes on all around us in microscopic realms.  BALOs could be harnessed in many different ways to improve our health: just the Swedish experiment of removing chlorine showed that it’s not always necessary to use harmful chemicals to kill bad microbes.  Although a lot more research needs to be done, it’s good to know that there are bacteria out there that are on our side! 

What are Probiotics for the Air?

Probiotics have been around for a long time, even millenia!  Probiotics are live, active microorganisms ingested to alter the gastrointestinal flora for health benefits. They often are referred to as good bacteria in the gut and compete with bad bacteria to support the body in establishing optimal digestion and aid immune function. (An Introduction to Probiotics)  Now, they didn’t always exist in “capsule” form.  In fact, if you look in  the refrigerated section of the grocery store, probiotics are the cultures found in kefir, kimchi (fermented cabbage), kombucha (a fermented tea), miso (a fermented soybean paste), pickles, sauerkraut, tempeh (another fermented soybean food) and yogurt.  The common thread of all these foods includes fermentation, which is the breaking down of organic substances through the action of enzymes.  Bacteria are the carriers of these enzymes, so as the fermentation occurs, these good bacteria increase.  When we ingest fermented foods, the bacteria populate our intestines for better digestion. (Check out our article on fermentation!)

Now that you know probiotics have been in foods since antiquity, probiotics for the air and surfaces in your home is a relatively new concept.  BetterAir was the first company to use probiotics in an air purifier.  According to BetterAir President Tom Staub, “Allergens, pathogens, germs etc. do not grow in the air, but are born and propagate on surfaces and objects.  Since they are microscopic they are then propelled into the air by minute movements of air such as the wave of a hand across a tabletop or fall off a foot upon stepping onto carpet.”  BetterAir’s proprietary probiotic formula consumes organic allergens often found inside the built environment like pollen, mold spores, pet dander, and dust mite fecal matter. Staub continues, “They also consume the food sources that germs and pathogens need in order to multiply and propagate thereby minimizing their presence. Fewer pathogens on surfaces and objects results in cleaner air, surfaces and objects. “ (BetterAir: The First Air Purification Device To Utilize Probiotics To Clean Your Home’s Air)

Considering that probiotics contain live bacteria, an air purifier that sprays them into the air may be, well, a little scary to some!  Rest assured, however; BetterAir’s proprietary formula’s active ingredient consists of naturally occurring (non-GMO), safe and effective Bacillus strains.  

Bacillus encompasses a large number of bacteria types, and some are harmful, but many are helpful, such as the medically useful antibiotics  produced by B. subtilis (bacitracin). (bacillus bacteria)  In order to produce and market Enviro-Biotics, BetterAir passed all the required tests by EPA standards at EPA-certified GLP (Good Laboratory Practice) labs, became EPA registered (94339-1, August 2021), and the US Food and Drug Administration (FDA) declared Enviro-Biotics as GRAS – Generally Recognized as Safe.  Finally, it has been certified by many government and private healthwatch organizations.  So, the liquid dispersed by BetterAir systems is safe for people, pets and plants.  

The following video screenshot shows how a petri dish treated with drops of Enviro-Biotics (right) forms a barrier that stops black mold from growing, unlike the untreated dish on the left.  This is visual proof of what their technology claims: microscopic sized Environmental Probiotics form a protective layer of microflora on all surfaces and objects, where the probiotics agents deny pathogens (mold and bacteria) access to nutrients (food), therefore obstructing and disabling growth of pathogens on these surfaces and objects.  In addition, and concurrently, Enviro-Biotics consumes harmful organic particles that are the source of allergies and diseases. Since dust and dander will be in every household to some extent, by introducing good bacteria, these allergens are used to feed the good and starve the bad bacteria.

Source: The Power of Enviro-Biotics

If your home is in an exceptionally dusty or polluted area, BetterAir has also combined a probiotic air purifier and a HEPA air purifier. 

Another way to use probiotics is to clean with them.   HomeBiotic has spray bottles for spritzing the air and surfaces that are smelly, which starves bad bacteria and protects from its regrowth for up to 5 days.  Their cleaning bundle has tablets that dissolve in water to make a non-toxic, powerful cleaning solution that is safe to the homebiotic bacteria they promote, and nano-sponges that clean without spreading germs around your home.  The tablets are made of washing sodas and citric acid, which are completely safe for people and pets. Citric acid in the right dose, for example, is an EPA-approved, non-toxic sanitizer that kills norovirus.  However, citric acid should not be used on natural stone or marble, wood, delicate surfaces or electronic screens because it may damage them.

Although probiotics are not a “silver bullet” for all airborne contaminants, they may help allergy sufferers and may help you to maintain health better when seasons change and new contaminants come into the home.  It’s like your gut: taking probiotic supplements feeds the good bacteria and doesn’t leave a lot of room for the bad to multiply out of control.  Therefore good effects of probiotics in the home depend on consistent use over a period of time, and avoiding chemicals like bleach that kill both good and bad bacteria indiscriminately. With new technology advancing everyday, it probably won’t be long before we can “see” exactly what is colonizing our homes and bodies, and then get tailored solutions to optimize it.  Since probiotics already live outside in the natural world (in soil, wood and other natural surfaces), like ions are present in fresh outdoor air, bringing probiotics indoors could be a good idea for keeping our homes healthy with natural methods and substances!