Psoriatics: Saccharomyces Boulardii Is Dangerous!

Even though Saccharomyces boulardii is one of the most popular digestive and SIBO supplements it is nowhere near as safe and perhaps also effective as you might think.

Yes, I know there is another article on this blog – “Probiotics are Useless, Saccharomyces Boulardii as SIBO Cure”.

I would not oppose the information stated in that blog post which was written in order to explain why bacterial probiotics may not be the best way how to cope with digestive or other chronic inflammatory health problems.

I am still sure that taking bacterial probiotics won’t cure SIBO (at least in most people) because small intestine is not designed and intended to host the billions and billions of bacteria. Not even the Lactobacillus species, because lactic acid produced by those bacterial strains damages the lining of the small intestine which may lead to villous atrophy (worsening of the nutrient assimilation) and increased intestinal permeability.

So, if you wanted to suppress the growth of bacteria in the small intestine I would say that probiotic yeast makes a lot more sense than probiotic bacteria – mostly if bacteria itself are bad if overgrow in the small intestine.

But, who said that Saccharomyces boulardii may not or won’t overgrow in the small intestine?

And here is the thing about Saccharomyces boulardii you probably don’t know and most people never heard of…

Well, never heard of… most people think that it is completely the opposite what I am going to tell you in the next lines.

Saccharomyces boulardii is a strain of Saccharomyces cerevisiae

Yes, this is unfortunately true and most people don’t know that.

Saccharomyces boulardii is very similar to other yeasts from Saccharomyces cerevisiae “family” – like Brewer’s yeast, Baker’s yeast, yeast responsible for fermentation during the winemaking…

Most people want to avoid those yeasts even though those yeasts are dead after the pasteurization or baking process.

This is funny because people won’t eat a piece of bread due to its yeast content but they are OK with eating the similar yeast (S. boulardii) as supplement in the capsules.

Saccharomyces boulardii really isn’t some “miraculous” probiotic yeast which would be completely different than all other yeasts. [1]

The next abstract comes from the scientific article “Seven cases of fungemia with Saccharomyces boulardii in critically ill patients”:

Saccharomyces boulardii (Sb) is a particular strain of Saccharomyces cerevisiae (Sc). This viable yeast is used in intensive care adult patients, delivered in packets of 500 mg, for preventing diarrhea associated with antibiotics or enteral feeding at a regimen of 1-2 g/day. Between June 1996 and October 1998, seven cases of fungemia with Sb occurred in a 12-bed intensive care unit (ICU). All the patients concerned were severely ill patients, mechanically ventilated, treated by broad spectrum antibiotics with central venous catheter and were pretreated with Sb, except for one patient. In this study, Sb was identified by specific mycologic methods and confirmed the genomic identity between isolates of blood culture and yeasts from the treatment packets, contrary to a few other reports concerning Saccharomyces species published in international literature. The hypothesis discussed for explaining these cases of Sb fungemia are: (1) an intestinal translocation of Sb administered at a high dosage in severely ill patients, (2) a contamination of the central venous catheter, especially in the patient not pretreated with Sb and (3) a massive colonization of critically ill patients by the yeast as has been reported for Candida species. We note that cases of fungemia with Sc and Sb have become more and more frequent in the international literature during the last 10 years and we do not recommend administering Sb treatment in critically ill patients.
” [1]

Fungemia is a fungal/yeast infection of the blood. In this diagnosis the blood contains detectable and usually significant amounts of yeast or fungal cells without spreading into the host’s organs.

As you read in the quoted text above the patients treated with antibiotics and (those having) central venous catheter belong to the risk group of people who should not be administered Saccharomyces boulardii.

Image Source: staff (2014). “Medical gallery of Blausen Medical 2014”. WikiJournal of Medicine 1 (2). DOI:10.15347/wjm/2014.010. ISSN 2002-4436

The authors of the article suspect the intestinal translocation of the Saccharomyces boulardii as No.1 cause of fungemia when administered at high dosages.

The another possible ways how this yeast may cause fungemia are via contamination of central venous catheter and standard colonization of critically ill patients as we are used to see in case of Candida species.

Saccharomyces boulardii may cause even septic shock. The researchers found no other explanation as the cause of septic shock in one patient who was administered this yeast.

Four cases of Saccharomyces boulardii fungemia, a very rare side effect of Saccharomyces boulardii therapy, are reported. The clinical impact of Saccharomyces boulardii infection appeared to be moderate. However, even though organ involvement was never demonstrated, septic shock with no other etiology was observed in one of our patients. All patients had an indwelling vascular catheter. Contamination of the air, environmental surfaces, and hands following the opening of a packet suggests that catheter contamination may have been a source of infection. To prevent catheter contamination it is recommended that packets or capsules of Saccharomyces boulardii be opened with gloves, outside the patient’s room.
” [2]

Even though the scientists suspected the catheter as way the infection developed I think that ingestion of Saccharomyces boulardii might be very possibly the way how yeast get into the blood.

Considering how small amounts of yeast might get into the air, on the environmental surfaces or on hands it is not probable (at least in my opinion) that this (generally considered) non-pathogenic yeast would lead to fungemia and even septic shock.

Another fact is that people with any form of catheter have usually some serious health problem and the chances are that they are immunocompromised already.

Here is another report of fungemia caused by probiotic yeast.

Saccharomyces boulardii is widely used as a probiotic compound and is generally thought to be safe. We report one case of fungemia caused by Saccharomyces cerevisiae occurring in an elderly patient treated orally with S. boulardii in association with vancomycin for Clostridium difficile colitis. We do not recommend administering this viable yeast particularly in debilited patient with active colitis.
” [3]

In one scientific magazine the authors presented “a case report of a 79-year-old woman with rheumatoid arthritis, who after a bowel resection developed S boulardii fungemia. Her postoperative course was complicated by nutritional problems, anaemia and several nosocomial infections including recurrent C difficile associated diarrhoea. The diarrhoea was treated with metronidazole, vancomycin and Sacchaflor. After 13 days of treatment, the patient developed fungemia with S boulardii.” [6]

The yeast supplement was immediately discontinued and the 18 days treatment with amphotericin B was successful.

Amphotericin B as an intravenous antifungal drug is considered to be the strongest antifungal medication the science provided up to this day.

The latest report of Saccharomyces boulardii associated fungemia I found in a scientific literature comes from 2014.

The yeast Saccharomyces boulardii is a biotherapeutic agent used for the prevention and treatment of several gastrointestinal diseases, such as diarrhoea caused by Clostridium difficile, in addition to the antibiotic therapy. In this study we report a case of Saccharomyces cerevisiae fungemia in a patient with Clostridium difficile-associated diarrhoea (CDAD) treated orally with S. boulardii in association with vancomycin. The identification of the S. cerevisiae was confirmed by molecular technique. Fungemia is a rare, but a serious complication to treatment with probiotics. We believe it is important to remind the clinicians of this risk when prescribing probiotics, especially to immunocompromised patients.
” [4]

Intensive Care Unit and S. boulardii fungemia outbreak

In 2003 the Italian authors published a “report an outbreak of Saccharomyces cerevisiae subtype boulardii fungemia among three intensive care unit roommates of patients receiving lyophilized preparations of this fungus. The fungemia was probably due to central venous catheter contamination and resolved after fluconazole treatment.” [7]

They reported the 3 cases of Intensive Care Unit patients who developed Saccharomyces cerevisiae (boulardii) fungemia even though they didn’t receive any probiotic yeast themselves.

All three patients were prescribed a 400mg/day fluconazole therapy and recovered successfully.

How do those patients developed Saccharomyces cerevisiae (boulardii) fungemia?

A probiotic preparation labeled Codex (Zambon Farmaceutici, Vicenza, Italy) and declared to contain 250 mg of lyophilized Saccharomyces boulardii

had been in use at the ICU since 1999. It was usually administered by a nurse wearing standard latex gloves, who opened the package containing the probiotic powder and dissolve it close to a sink located approximately 3 m from the nearest bed in the six-patient room. For administration of the probiotic preparation, the full content of the package was directly poured into the cylinder of a 50-ml syringe to which 30 ml of saline solution was added. The probiotic suspension was finally administered via the enteral nutrition tube.

In October 2000 (just before the outbreak), the probiotic preparation had been administered to four patients but not to the three patients involved in the outbreak (cases 1 to 3) reported in this study. After the first two cases of fungemia occurred, the probiotic preparation was not used further for 3 months. Importantly, the third case of fungemia was diagnosed about 1 month after reintroduction of the probiotic preparation into prophylactic regimens. Consequently, the probiotic preparation was no longer used.
” [7]

As the authors concluded a “review of the literature showed that (i) fungemias can occur in immunocompetent patients and may contribute to morbidity and mortality in immunocompromised patients, (ii) enteral translocation of ingested microorganisms and CVC insertion site contamination are the main portals of entry into the bloodstream, (iii) prevention of CVC-related fungemias can be achieved by simple prophylactic measures, and (iv) fluconazole and amphotericin B are effective therapeutic options; CVC removal alone was also effective in some cases.

Finally, our study emphasizes the risk of infection if the package containing the lyophilized fungal preparation is opened in a patient’s room and without proper infection control precautions, such as changing gloves before administration of the probiotic preparation and careful hand washing.” [7]

Self-injecting of Saccharomyces boulardii by a street drug user

Even though self-injecting of Saccharomyces boulardii in small amounts is not necessarily life-threatening – as you may read down below – keep in mind that 15mg of yeast in non-immunocompromised person is something different from taking capsules which each contains 500mg of this supposedly non-pathogenic yeast.

A 19 year old schizophrenic girl was admitted with fever to hospital. She had been self-injecting hard kind of drugs for years before. She is HIV and hepatitis C negative. On day 0, she self-injected intravenously 1 ml of water containing approximately 150 mg of amoxicillin obtained from a capsule and 15 mg of Saccharomyces cerevisae (boulardii) contained in an ultra-levure® capsule, a probiotic used to prevent or treat diarrhea. Immediately after the injection, she experienced chills that resolved spontaneously; 3 h later she developed chills and a 40 °C fever. Her blood was then sampled for culture.

She recovered spontaneously on the day +2, date when the result of the culture turned out positive for Saccharomyces cerevisae (boulardii).

She did not receive any antifungal treatment, and she is now doing well.
” [5]


It is sure that any type of immunosuppression will increase the chances of serious yeast infection when supplementation with Saccharomyces boulardii is present.

You know, the cancer patients who undergo a chemotherapy may develop a serious fungal infection and even die from it! That’s why they shouldn’t eat anything fermented (bacteria and fungi are present) and surely not mould-ripened cheese.

If any microorganism is not very invasive and generally pathogenic, in those with very compromised immune system virtually ANY microorganism may cause a serious and life-threatening problems.

Now, the question is if we – psoriatics – are immunocompromised?

The answer to this question is more complex but just to satisfy your curiosity I say this.

In population of people who were diagnosed as having the AIDS, psoriasis is about twice as prevalent as in population without the AIDS diagnosis.

Do I recommend to take Saccharomyces boulardii as a probiotic?

Sorry, but with the information I know today, I would not recommend to take this yeast to anybody!!!

If I wanted to get rid of Candida or some pathogenic bacteria I would rather used the essential oils which proved to posses the strong anti-microbial activity and high safety.

Then you have coconut oil, colostrum and in serious life-threatening cases there are the doctors who will prescribe the strong anti-fungal drugs.


1) Lherm T, Monet C, Nougière B, Soulier M, Larbi D, Le Gall C, Caen D, Malbrunot C. Seven cases of fungemia with Saccharomyces boulardii in critically ill patients. Intensive Care Med. 2002 Jun;28(6):797-801. Epub 2002 May 10.
2) Hennequin C, Kauffmann-Lacroix C, Jobert A, Viard JP, Ricour C, Jacquemin JL, Berche P. Possible role of catheters in Saccharomyces boulardii fungemia. Eur J Clin Microbiol Infect Dis. 2000 Jan;19(1):16-20.
3) Cherifi S, Robberecht J, Miendje Y. Saccharomyces cerevisiae fungemia in an elderly patient with Clostridium difficile colitis. Acta Clin Belg. 2004 Jul-Aug;59(4):223-4.
4) Santino I, Alari A, Bono S, Teti E, Marangi M, Bernardini A, Magrini L, Di Somma S, Teggi A. Saccharomyces cerevisiae fungemia, a possible consequence of the treatment of Clostridium difficile colitis with a probioticum. Int J Immunopathol Pharmacol. 2014 Jan-Mar;27(1):143-6.
5) Lola Cohena, Stéphane Ranqueb, Didier Raoultc. Saccharomyces cerevisiae boulardii transient fungemia after intravenous self-inoculation. Medical Mycology Case Reports, Volume 2, 2013, Pages 63–64
6) Julie Bjerre Thygesen, Henning Glerup, and Britta Tarp. Saccharomyces boulardii fungemia caused by treatment with a probioticum. BMJ Case Rep. 2012; 2012: bcr0620114412.
7) Marco Cassone, Pietro Serra, Francesca Mondello, Antonietta Girolamo, Sandro Scafetti, Eleonora Pistella and Mario Venditti. Outbreak of Saccharomyces cerevisiae Subtype boulardii Fungemia in Patients Neighboring Those Treated with a Probiotic Preparation of the Organism. J Clin Microbiol. 2003 Nov; 41(11): 5340–5343.

4 Responses

  1. Anonymous says:

    Critically ill patients!!!!!! inmuno-suppressed…

    • John says:

      You never read the whole blog post.

      And if something like S. boulardii in trace amounts can cause huge health complications then you think taking 1,0 – 1,5 grams of it can not do anything bad in average individual?

  2. J says:

    All probiotics if they are introduced systemically can kill you. Why the focus on ( and scare people) about something that literally saves people’s lives who have C-diff. A very small minority of people that take any pharmaceutical have a life threatening reaction. Do you can the drug??? How about cars??? Everyday a small minority of people die in car crashes, do you stop using cars forever. This is not a balanced article!

  3. Kathleene Parker says:

    I seem to be using S. Boulardii–despite advanced, MAJOR SIBO–just fine. But I will heed the caution in this because I do know I can have sensitivities to molds/yeast, but then, I have sensitivities to EVERYTHING, thanks to modern medicine! So, my takeaway from this is that, yes, I will use S. Boulardii but at lower dosages and closer scrutiny of what’s going on. My position is that I cannot tolerate so much, that I must start somewhere in a world where one side says, “Do this!” and someone else says, “No, don’t do that!:

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