Should I Feed My Dishwasher Probiotics?

The short answer is, "Yes"!

We get some interesting insight into the fascinating world of microbiology in a study that was published January 12, 2018 in Applied and Environmental Microbiology, American Society for Microbiology where researchers uncovered some remarkable findings about dishwasher health. According to the researchers, despite a dishwasher's extreme conditions generated during a cleaning cycle (i.e., high temperatures, high and low PH, high NaCl concentrations, detergents, strong currents of water), microbes survive!

"Fungal and bacterial diversity in biofilms isolated from rubber seals of 24 different household dishwashers was investigated using next-generation sequencing. Bacterial genera such as Pseudomonas, Escherichia, and Acinetobacter, known to include opportunistic pathogens, were represented in most samples. The most frequently encountered fungal genera in these samples belonged to Candida, Cryptococcus, and Rhodotorula, also known to include opportunistic pathogenic representatives." (January 12, 2018, Microbial Diversity and Putative Opportunistic Pathogens in Dishwasher Biofilm Communities in Applied and Environmental Microbiology, American Society for Microbiology,

Interestingly, this study demonstrates that bacteria, such as Pseudomonas, which might be considered problematic from a public health perspective, can survive extreme and harsh conditions inside a dishwasher during a cleaning cycle. Professor Gunde-Cimerman of microbiology at the University of Ljubljana in Slovenia worked on the study:

"It is possible for dishwasher microbes to break free from their home: They can get out via waste water, or through the hot air produced at the end of the dishwasher cycle, Gunde-Cimerman said. So one way to keep the microbes contained is to avoid opening the dishwasher before it has cooled down, according to Gunde-Cimerman." October 24, 2019,

Pseudomonas and Bacteria..."oh my"!

I remember my experience from many years ago working in the fitness industry. On a regular basis, we had to submit hot tub water samples to the Provincial Government for testing. It became a serious matter if a sample was deemed a "fail" because it meant that the hot tub would be immediately taken out of operation and we would then have to implement measures to sanitize the basin and all the water circulation pipes. Once the water was replaced, and circulating, brand new water samples would again be submitted to the provincial lab for testing in order to gain approval to operate for use by the public. An incidence such as this was unusual, but illustrates that from a public health perspective, detection of this kind of bacteria was serious.

Microbial Diversity is Everywhere

This information is not meant to frighten anyone, because microbial diversity is everywhere and necessary, but it does serve to illustrate the presence of potentially problematic bacteria even after being exposed to the dishwasher's extreme and harsh conditions. A key point being raised in the study, is the potential for infection and a key issue of concern for those managing a compromised immune system:

"The bacteria are found widely in the environment, such as in soil, water, and plants. They usually do not cause infections in healthy people. If an infection does occur in a healthy person, it is generally mild." (October 24, 2019,


Peacekeeping in the Face of Destruction

If you could give probiotics (beneficial bacteria) a persona, it would be more like that of a "microbial peacekeeper". These bacteria are soil-based and work as agents to promote harmony and balance at the microscopic level. They are strong to thwart off what we consider pathogenic threats, while gentle towards people, pets and the planet.

When all that we have known for decades is to deal with unwanted microbes by killing (i.e., biocidal), it is quite the paradigm shift to accept something so elegant and simple as probiotics to mitigate harmful effects of pathogens, bacteria, fungus and viruses.

The gravity of using chemicals and disinfectants is that they are counterproductive to achieve a clean and healthy indoor environment. Unfortunately, with chemicals being applied, it creates favourable conditions for pathogens, bacteria and biofilm to flourish. Chemicals and disinfectants certainly kill "unfriendly bacteria", but they also kill off "friendly bacteria"; wholesale destruction of organisms. What remains is an "all you can eat buffet" food source as a result of the microscopic wasteland of carcasses strewn all around. Pathogenic organisms sense this feasting opportunity, flying in from the air, creeping out of nooks and crannies and emerging from the protective cover of biofilm. These organisms gorge themselves and thrive to create microbial chaos (i.e., the creation of more biofilm)!



On our website, we go into some detail on the subject of biofilm and why it is of such concern. See our FAQ section:

Our Probiotics Deconstruct Biofilm

That's correct, our probiotics deconstruct the biofilm! There are three mechanisms that are occurring when probiotics are applied.

The Probiotic Triple Threat!

  1. Competitive Exclusion
  2. Quorum Sensing
  3. Penetration and Removal of Biofilm

Competitive Exclusion happens when you apply armies of probiotics (i.e., friendly bacteria) to occupy surfaces. Millions of them drop onto the scene in a full-out invasion, outcompeting harmful pathogens for food and space. Once the "harmful bacteria" die, the probiotics continue to consume dead organisms.

Quorum Sensing is a term to describe the communication that exists between bacteria. Basically, the probiotics are telling the pathogens to stay away from an environment that is no longer supportive to their existence in the area. These probiotics will hold them at bay for 3-5 days. In other words, the unwelcome visitors are being invited to leave!

Penetrating and Removal of Biofilm is the final wave of the Triple Threat. Probiotics penetrate and weaken the protective matrix of trapped dirt, viruses, mold and fungi (i.e., biofilm) and continue to eat away at if for 3-5 days! This makes it very easy to include the essential step to physically remove the debris with a cleaning cloth.

Damage to Materials

Chemicals and disinfectants generally require personal protective equipment and ventilation. When you read the ingredient list on many of these cleaners that are purported to be safe, you quickly realize they are toxic and destructive to materials. For example, your dishwasher has rubber seals that break down when treated with chemicals and even natural cleaners, such as vinegar and essential oils. When the seals are damaged, it leads to water leaks and requires part replacements and repairs.

Indoor Air Quality is Compromised

In addition, the chemicals that are being used in the effort to maintain a clean indoor environment compromise air quality. Contaminants are released into the air and can trigger asthma attacks and aggravate allergic conditions.

A Dose of Prevention

There is something you can include in your cleaning routine, and that is to spray probiotic mist into your dishwasher in between times when you run it. When it comes to a more thorough cleaning of your dishwasher appliance - which should be done on a regular basis - you can use the Probiotic All Purpose Cleaner. Especially in light of the information that was included previously about the biofilm that forms on the rubber seals, it is very important to remove the grate at the bottom of the unit and clean off anything that may have accumulated, such as food; clear out any debris. Regular use of probiotics to maintain your dishwasher will go a long way to mitigate the proliferation of unwanted bacterial visitors. And because bacteria is most often the culprit of generating unpleasant odours, probiotics are a very good way to improve upon your home's air quality. It is so easy to give your dishwasher a beneficial dose of probiotic protection, keeping it free from the proliferation of harmful pathogens.