Does Rectal Ozone Kill Good Bacteria in the Gut?

by | Feb 4, 2020 | 12 comments

Rectal insufflations are one of the most popular ozone therapy applications: their effect is supposed to be equivalent to intravenous ozone therapy without requiring needles or nurses. But ozone is a potent antibacterial gas and during rectal insufflations it’s introduced into the very area which is rich with beneficial microbes: the large intestine. So you may be asking yourself: will ozone kill good bacteria in my gut?

After some thorough research, I found out that no studies have ever been performed which tested the gut biome of patients before and after rectal ozone insufflations, so it’s not known what effect they have on the gut flora.

There are anecdotes of people reporting improved digestion after ozone treatments, just like there are reports of people saying that rectal ozone treatments gave them cramps, pain, and bloating. [5] There are many studies which show that ozone can reliably kill many bacteria which can be commonly found in the human gut.

Let’s look at the research one by one:

How could ozone kill good bacteria?

Ozone is known to be an excellent sterilizing agent. It is able to kill a wide range of bacteria and viruses [7-18] and is used to sterilize laboratory equipment [19]. The gas has also been tested on one of the most resistant bacteria and deemed appropriate to use for the sterilization of medical appliances. [18]

Ozone is able to kill both disease causing bacteria [6-17] and some beneficial strains which are found in the human gut. [7] [9] [14] [16]

But the findings of studies which have been performed in glass dishes are often not transferrable to humans. Nevertheless, due to the fact that during rectal insufflations the gut biome is directly exposed to the gas – just like during experiments in petri dishes – it’s something that should be examined.

Another factor to consider is that most of the studies used ozone concentrations between 1mg/L and 25 mg/L. Rectal insufflations on the other hand are performed with ozone concentrations of on average 40 mg/L with some going as high as 80 mg/L.

The fact that most beneficial microbes live in the upper layer of the mucus, the part which is directly exposed to the ozone during rectal ozone treatments, may contribute to the risk of damaging the biome [30].

Is there a study which shows that ozone improves the gut biome?

There is a study which is often quoted as proof that rectal insufflations not only do not damage the gut biome, but that they can even improve it. [1]

Let’s look at what the study really shows:

Two doctors took 34 participants with assumed gut dysbiosis, so a disturbed gut biome, and subjected them to regular rectal insufflations and gave them ozonated water to drink. Afterwards, there were significant reductions in symptoms like bloating, gas, bad breath, diarrhea, constipation, or pain. The study designers came to the following conclusion:

“(…) the rectal insufflation association of the oxygen-ozone mixture with the intake of hyperozonated water by mouth, has recorded quite encouraging results to such an extent that the authors have concluded that this synergy of approach can be considered as a fundamental method in the treatment of intestinal dysbiosis in those patients resistant to other treatments.

The problem is that this study never looked at the gut biome neither before nor after the administration of rectal ozone insufflations. As the “methods and materials” and the “results” sections of the study reveal, the study participants never had to undergo stool tests. No results of bacterial strains are discussed nor presented prior nor after the rectal ozone intervention.

Consequently, this study was unable to prove what it claims to prove. The study designers assumed that the digestive issues of the study participants were caused by gut dysbiosis without ever actually looking at their gut flora.

Fermented foods like sauerkraut or kimchi could potentially counteract any damage to the gut biome. 

Other studies about ozone therapy and digestion

Another study that is quoted as proof that ozone could be beneficial for the gut biome is a rat experiment. [2] During the study rats were given ozonated water by gavage (orally) and intraperitoneally. The intraperitoneal administration of ozone is a procedure where the gas is applied through an incision in the abdomen and impacts the outside of the intestines. The insides, where the bacteria reside, are never exposed to the ozone. So the findings of the study are irrelevant to rectal insufflations.

Another experiment published on Brazilian’s Institute for Ozone website ( describes how dogs and cats were subjected to rectal ozone insufflations and claims that this “Yields Successful Outcomes for Dogs and Cats with Fecal Transplants”. [3]

Given that the animals were at the same time given “digestive enzymes, probiotics, whole food glandulars, and raw meat diet” on top of fecal matter transplants in order to help “establish a hospitable environment for the new biome” it’s impossible to know which of the many interventions resulted in the positive outcomes. 

Does ozone spare the good bacteria in the gut and only kills the bad one?

Some assume that ozone is able to selectively kill the bad bacteria and let the good bugs survive. This belief is based on two erroneous asumptions:

  1. That ozone, being a form of oxygen, would spare aerobic (oxygen loving) and only kill anaerobic (oxygen hating) bacteria, and
  2. that aerobic bacteria are the beneficial bacteria, and the anaerobic are the bad bacteria.

Both suppositions are wrong: up to 99% of our good gut bacteria is anaerobic and resides in the large intestine. [28]

Some of the most dangerous bacteria are aerobes or facultative aerobes (meaning they can live in an oxygen rich environment but don’t need it to survive). Here just a few examples: E. coli [7] [11] [12] [14] [22], Salmonella [15] or Bacillus anthracis (also known as anthrax) [23].

Ozone has been shown to kill all of those aerobic bacteria successfully at much lower concentrations than is commonly used during rectal insufflations.

Did Prof. Bocci believe that ozone was good for the gut biome?

Prof. Bocci was a famous Italian ozone doctor. He wrote the book “Ozone – a New Medical Drug” which is regarded by many as the most important work on ozone therapy.

Prof. Bocci is often quoted as someone who believed that rectal ozone insufflations could improve the gut biome.

Unfortunately, this is not correct.

Here is what Prof. Bocci really said:

“Whether RI (rectal insufflations) with a daily input of oxygen-ozone can re-equilibrate the bacterial flora and lead to normal immunoreactivity remains to be demonstrated (and explained), although anecdotal results suggest a beneficial effect.” [4]

This is the only statement I could find in his book on the topic. Nowhere in this sentence does he express a personal belief on anything, including that rectal insufflations could reestablish the gut flora.

He merely speculates that this could be the case based on anecdotes after stressing that no research exists to substantiate nor refute this idea.

But: he does not explain what those anecdotes show: do they show results of stool tests taken before and after the administration of rectal insufflations, or do they simply show improvements in patients’ digestion?

It’s not clear, since he does not elaborate on it.

But it may be good to keep in mind that Bocci’s speculations didn’t always pan out, see his theory about rectal insufflations being possibly equivalent to major autohemotherapy. 

After postulating this idea, he then set out to conduct experiments to find out if his theory was correct, just to come to the conclusion that it wasn’t. [24]

But in the meantime his speculations had already caught the imagination of the ozone therapy world and he spend the following years trying to set the record straight about the alleged systemic effect of rectal insufflations, after his own studies showed that ozone never penetrates the mucosal layer of the gut. [25] Given that the idea is still largely circulated among ozone practitioners, it appears that he was unsuccessful in this endeavor.

Limiting rectal insufflations to the lower part of the large intestine, the rectum, should minimize any possible damage to the gut biome. 

Does it make sense to take probiotics to reduce the possible damage caused by rectal ozone insufflations?

Some ozone doctors instruct their patients to take probiotics when undergoing rectal insufflations to make up for the possible destruction of the gut biome. Does this make sense?

Probiotics could have many health benefits, and there is anecdotal evidence of digestive issues improving when patients supplement with probiotics.

But: there are only around 20 commercially available bacterial strains plus maybe another 50 if taken into account the earth based organisms. In contrast, research shows that a healthy human gut could contain anything between 1,000 to 5,600 different strains. [28] [29]

So a better solution to replenish the good bacteria appears to be to eat fermented foods like kimchi, sauerkraut, yoghurt, or kefir. [27]

But fermented foods come with a huge disclaimer: they are very high in histamines, so people who suffer from histamine intolerance may not be able to tolerate them. Same applies for probiotics: many of them produce histamine and can make histamine reactions worse. [26]

Why is it a good idea to be cautious about rectal ozone insufflations?

Current research has only begun to uncover the importance of our gut biome, but more and more studies emerge which give it far reaching implications for our health. Here some examples:

A study on rats showed that when rats where transplanted stools from autistic kids they also developed autistic like behavior. [32]

Autistic children which received fecal transplants from healthy donors saw their autism symptoms reduce by up to 50%. [31]

Studies performed on animals and postmenopausal women showed that supplementation with probiotics can increase bone density. [33]

The lack of the gut bacterium oxalobacter formigenes most likely increases the risk of developing kidney stones. [34]

The more antibiotics people take, the higher their risk of developing kidney stones. [37] Is it possible that similar calcifications also happen in the brain and other organs?

We know that C. difficile infections arise after the use of antibiotics which destroy many of the good bacteria that keep C. difficile in check. [35] A study found that in the US alone 29,000 people died because of C. difficile infection in a single year. [36]

Another rat study showed that rats which had a nearly sterile gut had impaired brain function when compared to control rats. [38]

Given that ozone is a potent bactericidal agent which has been shown to be able to even kill bacteria which have become resistant to antibiotics [14], it may be better to err on the side of caution and try other methods first. 

How can one minimize the potential damage to the gut bacteria when doing rectal insufflations?

Given that we don’t know what impact rectal insufflations have on the gut biome, it makes sense to approach rectal insufflations carefully.

Here a few suggestions:

1. Keep the ozone volume low at maximum 200 ml per insufflation. This should limit the reach of ozone to the lower part of the intestine.

2. If you’re a woman, do vaginal insufflations instead

If done long enough, vaginal insufflations appear to penetrate the lower abdomen and improve the digestion without exposing the good gut bacteria directly to the ozone.

3. If you’re a man, do this instead:

take Oxy-Powder, or Homozon or drink ozonated water. This will only impact the small intestine, which is supposed to be devoid of bacteria anyway, but it may give you a similar or maybe even greater benefit than rectal insufflations. Or do ozone saunas and direct the ozone stream towards your abdomen while you sit in the sauna box. This may treat your intestine from the outside.

4. Take extra probiotics

If you’re not histamine intolerant: eat fermented foods. Or take probiotics which do not produce histamine. [26]

Do you like shooting ozone up your bum and don’t care about the possible implications? Or do you prefer to do something else? Tell me all about it in great gory detail in the comments below 😉 .



[1] “The use of ozonated water and rectal insufflation in patients with intestinal dysbiosis

[2] “Effect of Ozone on Intestinal Epithelial Homeostasis in a Rat Model”

[3] “Ozone Therapy Used Instead of Antibiotics for Micro-Biome Restorative Therapy Yields Successful Outcomes for Dogs and Cats with Fecal Transplants”

[4] Prof. Velio Bocci “Ozone – A New Medical Drug”, page 54

[5] “The Ozone Group”, a Facebook group

[6] “Efficacy of ozone on microorganisms in the tooth root canal.” 

[7] “Antimicrobial Effects of Ozone Gel Against Periodontal Bacteria”

[8] “Effects of Gaseous Ozone Exposure on Bacterial Counts and Oxidative Properties in Chicken and Duck Breast Meat”

[9] “Inactivation of Bacteria and Coliphages by Ozone and Chlorine Dioxide in a Continuous Flow Reactor”

[10] “Comparative inactivation of poliovirus type 3 and MS2 coliphage in demand free phosphate buffer by using ozone”

[11] “Ozone-induced damage of Escherichia coli K-12.”

[12] “Bactericidal activity of ozone against Escherichia coli in whole and ground black peppers.”

[13] “Activity of ozonated water and ozone against Staphylococcus aureus and Pseudomonas aeruginosa biofilms.”

[14] “Effect of low-dose gaseous ozone on pathogenic bacteria”

[15] “Ozone Inactivation of Pseudomonas aeruginosa, Escherichia coli, Shigella sonnei and Salmonella typhimurium in Water.”

[16] “Ozone Inactivation of Lactic Acid Bacteria”

[17] “Characterization of efficacy and flow in a commercial scale forced air ozone reactor for decontamination of apples”

[18] “Evaluating the Potential, Applicability, and Effectiveness of Ozone Sterilization Process for Medical Devices”

[19] Ozone sterilizers for laboratory equipment

[20] “Effect of ozonated water on normal vaginal microecology and Lactobacillus

[21] Healthy gut bacteria

[22] “Efficacy of Ozone Against Escherichia coli O157:H7 on Apples”

[23] “Inactivation of Bacillus anthracis Spores”

[24] “The rectal insufflation is not the best administration route for ozone”

[25] “Important details to be clarified about the effect of rectal ozone on the portal vein oxygenation”

[26] “Everything you need to know about probiotics”

[27] “Benefits of Sauerkraut”

[28] “Human gastrointestinal microbiota”

[29] “No ordinary gut check: Study finds plethora of microbes”

[30] “Role of mucus layers in gut infection and inflammation”

[31] “Autism symptoms reduced nearly 50 percent two years after fecal transplant”

[32] “Autism symptoms replicated in mice after faecal transplants”

[33] “Effect of Probiotics Supplementation on Bone Mineral Content and Bone Mass Density”

[34] “Oxalobacter formigenes May Reduce the Risk of Calcium Oxalate Kidney Stones”

[35] C. difficile infection

[36] Clostridium difficile, CDC

[37] “Oral antibiotics may raise risk of kidney stones”

[38] “Antibiotics that kill gut bacteria also stop growth of new brain cells”

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About the author:

PaolaI’m Paola the Crazy Old Ozone Lady behind The Power of Ozone. I’m a licensed naturopathic practitioner, natural health consultant, ozone therapy enthusiast, researcher, and ozone therapy analyst. I hold certificates in ozone therapy, hyperbaric ozone applications, Oxyvenierung, and the Andrew Cutler chelation. I own several ozone generators including a German hyperbaric 10 Pass machine. I have been using ozone for over 13 years, I’ve chelated with the ACC program for close to 5 years and I’ve been carnivore for nearly 1.5 years. This website serves as a resource for those who are interested in ozone therapy and other approaches to successfully manage chronic conditions. 


  1. Peter Lockwood

    so ozone will not kill off ALL the GOOD bacteria inc the protective Good Fungus in side the Vagina with vaginal insufflations ?? sorry you are cherry picking

    • Paola Dziwetzki

      Hi Peter,

      strange to see you here again. I thought you were only following PhDs?

      Please, show me exactly where I say that vaginal insufflations would not kill off all the good bacteria in the vagina?


  2. Deborah Bahm

    I listened to your theory on vitamin C and ozone as conjunctive therapies. I would say that what you need to address is that High dose vitamin C is an oxidative therapy and not a antioxidant therapy. So it would depend on the dose. High dose vitamin C correctly given has a different purpose than therapeutic Vitamin C therapy. Check out Dr. Contraras from Oasis of Hope, on youtube.

    Deborah Bahm, RN, MA

    • Paola Dziwetzki

      Hi Deborah,

      I’m well aware that high dose Vit C IV are a pro-oxidant therapy. I’ve posted about this on my FB page a number of times.

      But it still cancels out ozone – which is evident from patients’ reactions.

      I assume it’s because when you infuse the Vit C it takes time until it reaches a concentration where it’s a pro-oxidant.

      Until then it likely acts as an anti-oxidant and neutralizes ozone.


      • Deborah Bahm

        Would your suggestion be that you shouldn’t do these therapies together?

      • Paola Dziwetzki

        Hi Deborah,

        either that or space them apart by several hours.


  3. Stevy Stephens

    Sending many thanks for your commitment to sharing your experience with chronic illness and solutions that may help others resolve their health challenges. I admire all the time and effort you put into research. Your youtube channel has been essential in my efforts toward recovery! Added bonus in your candor and humor. I am grateful you are so driven!!!

  4. Tom Carnaffin

    Dear Paolo,
    I have been interested in ozone fir some 12 years and even looked at becoming an agent for a Taiwanese company of equipment manufacturers but unfortunately they got into financial difficulties and stopped production.
    Never the less I have a number if pieces of equipment from them and also America.
    This includes general purpose generators I use for house decontamination
    I also have a oxygen concentrator and O3 generator which I have reassembled with a double bubbler unit which I was going to bubble the ozone through olive oil to take if I contract this virus
    What do you think of that ???
    My second question is more of where would I find something
    I need to get a porous stone to use to ozonate water I seem to have mislaid mine can you advise where these are readily available from now

    Thanking you in anticipation for you possible kind help regarding my two questions

    Best regards
    Tom Carnaffin

    • Paola Dziwetzki

      Hi Tom,

      I think the ozone bubbling thing through olive oil is a great idea! I list it as one of the possible solutions if one contracted the Corona or some other infection.

      As to the porous stone: you don’t necessarily need it. You can just dip the silicone ozone output hose directly into the water. That’s what I used to do and it works just as fine.

      But if you want the stone, there are the following options:
      – Amazon: , those are made to bubble ozone through fish tanks
      – Here something more fancy from Promolife:
      – or this glass ware with a destructor attached to it:, the bubbler stone is already part of the glass contraption.
      – You can also order a bit cheaper solution from Promolife but it can take a few weeks for it to arrive since they are backordering stuff

      I hope those suggestions help.

      Thank you for your donation!


    • Paola Dziwetzki

      Yes, that’s the very first link in the Sources section.


  5. Whitne Drake


    Thank you for this information. I did my first ozone treatment last night, using suppositories. Rectal and vaginal.

    Earlier this year I had a DNA analysis done of a stool sample. Came back showing that gram negative bacteria and two fungi had taken over my body, completely wiping out all good bacteria. I’ve been using enzymes and herbs to treat biofilm, but it’s not enough. After just one ozone treatment, I have no gas, no gurgle gut, and no heartburn. I already take loads of probiotics. I am so excited about this success! I also have some EDTA suppositories to work with. So, I’m just figuring it out as I go. I’m going to get the Oxy power you mentioned as well.

    Thank you again


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