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Saccharomyces Boulardii: The Antibiotic Resistant Probiotic

Genes Mentioned

Our audience at Gene Food is interested in personalized nutrition and, often, supplements. As we have been digging into the research about genetic links to several digestive issues for new reports, it seemed like a good time to summarize the benefits of S. boulardii, a ubiquitous probiotic in the grocery aisle, and for good reason.

The French scientist Henry Boulard first discovered S. boulardii in 1920 after observing that certain locals in Indonesia were not succumbing to an outbreak of cholera. The healthier locals drank a tea made from the skins of lychee and mangosteen, from which Boulard was able to isolate S. boulardii as the protective yeast. The strain has been named after him ever since its discovery. 

S. boulardii basics

  • S. boulardii is a non-pathogenic yeast microbe that has been proven in multiple randomized clinical studies to be an effective probiotic, especially in the treatment of antibiotic induced diarrhea, traveler’s diarrhea, and other inflammatory bowel conditions.
  • In the case of lyophilized oral administration, as much as 3% of the living yeast of S. boulardii can be recovered in the fecal matter of recipients. This means the probiotic survives the digestive tract and is bioavailable.
  • S. boulardii has even been shown to increase serum IgA levels in mice, which has led researchers to speculate that S. boulardii may have the potential to boost the strength of the human immune system.
  • Because S. boulardii is a yeast microbe, it is not killed by antibiotics, and can be taken directly alongside a course of antibiotics.3

S. boulardii treats antibiotic associated diarrhea

As the name suggests, antibiotic associated diarrhea (AAD) is the problem of diarrhea as a side effect of taking antibiotics. 6

Clostridium difficile disease (CDD) is one of the most prevalent, and contagious, forms of AAD. CDD is potentially fatal. 7 In fact, repeated CDD infections are sometimes treated with Fecal transplant procedures, including at world renowned hospitals like the Mayo Clinic. Studies have shown that S. boulardii is the only effective probiotic in preventing CDD. 8

S. boulardii may help prevent traveler’s diarrhea

In addition to its important role in preventing incidents of CDD, S. boulardii has been proven to help prevent the occurrence of traveler’s diarrhea.

This is a big one for me when I’ve traveled to Asia. You want to jump right in and enjoy everything the locals do “Anthony Bourdain” style, but you also fear spending a large chunk of the trip in the bathroom.

This meta-analysis of studies found that probiotics, and especially S. boulardii, “significantly prevent traveler’s diarrhea.” 

S. boulardii and helicobacter pylori infection

Helicobacter pylori infection (H. pylori) is a stealth bacteria that is common worldwide, with an estimated 50% of the world’s population infected. 9 10 Although it can cause stomach ulcers and other symptoms, many people never know they have it.

H. pylori infection has been shown to increase the risk of gastric cancer by as much as 8 times. 11 1213 14

Patients receiving antibiotics to treat H. pylori infection had significantly lower incidents of AAD when taking S. boulardii. 15

Interestingly, this study hinted at the possibility that S. boulardii may “induce morphologic changes in H. pylori cells consistent with cellular damage.” Further research is needed to determine whether S. boulardii can in fact kill, or alter, H. pylori.

S. Boulardii and Candida

Candida is a pathogenic yeast that is found in everyone’s intestinal tract, but it can proliferate beyond healthy levels when our gut flora is disturbed.

S. boulardii has been shown effective at killing Candida, and suppressing expression of the inflammatory markers it produces. 12

S. Boulardii and Crohn’s disease & IBS

Crohn’s disease has a strong genetic link. S. boulardii was shown to help Crohn’s disease patients stay in remission, as well as improve measures of intestinal permeability, otherwise known as leaky gut.16

S. boulardii supplementation improved quality of life for IBS patients, but not bowel frequency or stool consistency.17

This meta-analysis found that, when compared with placebo, probiotics improved global IBS symptoms as well as reduced abdominal pain in IBS patients.18

S. Boulardii benefits in healthy people

This study found that intestinal inflammation makes it easier for S. boulardii to work, since the breakdown in the intestinal lining helps the yeast reach immune cells.

However, in a healthy intestine, the mechanism of action is likely not immune-mediated.

Instead, S. boulardii helps in maintaining a healthy bacterial state in the gut (i.e. S. boulardii acts as a microbiome fertilizer allowing healthy bacteria to flourish and crowding out more damaging strains), and by strengthening epithelial integrity, basically keeping the gut lining strong and preventing leaky gut. 19

Some studies suggest S. boulardii may help prevent colon cancer.

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Bottom line

The bottom line with S. boulardii is that it’s a proven supplement that has been shown the greatest efficacy in helping people with compromised gut health crowd out the “bad guys” so the “good guys” have a chance to flourish once again.

Dr. Aaron Gardner, BSc, MRes, PhD

Dr. Aaron Gardner, BSc, MRes, PhD is a life-scientist with a strong background in genetics and medical research, and the developing fields of personalized medicine and nutrition. Read his full bio here.

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  1. Kathy todd says:

    I was wondering if saccharimyces boulardi is good to take if you are taking ompreazole. I am trying to get off this medicine. My stomach is always feeling like it’s backed up. Not enough acid.

  2. Vkm says:

    My dad was on antibiotic course for 2 months ,along with antibiotics doctor suggested S. Boulardii..my dad found improve in digestion , he is diabetes type 2 patient he want to continue the S. Boulardii I want to know it is safe to take on every day basis for diabetes type 2 patient???

  3. B says:

    I am so very pleased that this product was recommended to me when I was very hesitant on taking a very strong antibiotic 4 5 days to rid myself of a bladder infection. When I took the probiotic with the antibiotic I was impressed by the fact that if I didn’t take it I was very tired but when I did take it with some of the antibiotic it seemed to give me more energy and after I finish the antibiotic I noticed right away that I had a discharge for 5 days that was quite pronounced and I went to my doctor for fear that there was something going on and my doctor said that because of the probiotic along with the antibiotic it got rid of all the toxins out of my system that was stored in my body for months. So I was quite pleased with this S.boulardii! !
    I have never heard of this product until I went to the health food store to inquire what I could do while I was taking my antibiotic and the woman recommended this product. And when I found out it did not interrupt the effect of the antibiotic I was so pleased. And the more I read about this the more I was recommending it to other people. It’s like there was a handshake and greet when the.S. boulardii and my antibiotic first entered my body and met.
    They both worked together. It was like a shovel was digging out the infection and interior teas and the s boulardii took it outside and dispose of the infection.
    It was so amazing how I could feel it in my body working together to rid myself of all the poisons that has accumulated in my body I don’t think any other probiotic would have the same effect with an antibiotic as this has..
    When I had some cabbage my stomach was very painful so I thought to myself what if I took S. Boulardii to see if it would do something and sure enough it got rid of my pain to my surprise. I’ve never had a probiotic get rid of pain caused by digestion…so interesting

  4. Kavita Devi says:

    Hi there,
    I am currently taking s boullardi. Can u tell me how im meant to be feeling during this treatment and how long till i feel better?
    Does it help pass bacteria through stool?

  5. Marie says:

    I had an endoscopy that showed GERD, gastritis, and IBS. I was put on Zantac, now Gastro. doctor wants me to go on a PPI. I’ve read how bad this is in so many ways. Do you have a Probiotic that you can recommend that would strengthen/heal my gut. Thanks so much

    • Sara says:

      Thank you for a good article! I’ve come back to it more than several times. I wonder if you or anyone else might have some input on this: My 90 year old mother was taking S. Boulardii during the last half of her 6 week course of Nafcillin [terrible diarrhea] and afterwards over 10 days while taking Cipro. Since then— she’s been taking S. Boulardii from Jarrow, one a day since mid December (about a month and a half now). She was using it to address the diarrhea and to ward off C. Diff. Do you think she can safely stop taking it now? I haven’t ever found any advice about when it’s no longer necessary.

  6. Eric says:

    Hi John-

    I had a question for you. I’ve read some reports saying that yeast and s bouldardii is high in histamine. If you have histamine intolerance, wouldn’t this make it worse? Did you have any increase in histamine issues while you took this supplement? Thank you

    • Hey Eric, it depends on what is causing the mast cell activation. It is true that some clinicians list S. Boulardii as contraindicated for people with histamine issues, however, clinicians like Dr. Neil Nathan in California suggest S. Boulardii when mold and yeast is to blame for the over active immune response. I believe Dr. Nathan would use gliotixin labs as part of a mycotoxin panel as one of the indicators.

  7. doreen scobie says:

    I’m taking the probio5 plexus supplement for candida overgrowth and bad bacteria in my intestines. It’s a premium product so stick with it. I have been on it for a month and feeling better. I also take the plexus vitalbiome, biocleanse, and the pink drink.

  8. Liz says:

    I have been taking Sacc B for 2 and a half months to support my anti inflammatory diet. My doctor recommended that you switch probiotic strains every 3 months so your body does not grow used to it. Can you recommend how exactly to use probiotics? Do I just switch them every 2 weeks? Just as support to the anti inflammatory diet. thanks.

  9. Jerry says:

    Since the Jarrow brand has MOS will it still help strengthen the gut or just pass through. Thanks for being here!

    • Kris says:

      Contact Dr.Alberto Snow. He has a website & a FB page. He is a world renowned Natruropathic Gastro Doc who is helping my kids with what was Misdiagnosed as Crohn’s. He is amazing & recommends S. Boulardii. He will help you!

  10. Ann says:

    I’ve recently been given a bottle of pro bio five advantage by plexus have you ever heard good or bad about this product.

    • doreen scobie says:

      I’m taking the probio5 plexus supplement for candida overgrowth and bad bacteria in my intestines. It’s a premium product so stick with it. I have been on it for a month and feeling better. I also take the plexus vitalbiome, biocleanse, and the pink drink.

  11. Tami says:

    How do you know if body reactions are side effects that are signs the yeast is doing its job or if they signal that one should stop taking them?

    After a week, my throat is sore, my tongue burns and is coated, my eyes feel red and scratchy, my ears ringi, my belly fills with gas and bloats and I’m still having soft stool and diarrhea.

    I started after a three-week vancomycin IV treatment for a MRSA infection. I have bad reactions to probiotics and read that could be because the glycocal mucous layer is damaged and s boulardi can repair it and crowd out Candida too.

    Prior to my vancomycin treatment, my integrative doctor had started me on a anti-candida supplement , but recommended I stop for a bit and take probiotics to rebuild after the antibiotic. Even on very small doses of probiotics, I am miserable with bloating and abdominal pain.

    Are these side effects normal and how long can they last?

    • Tami, these are questions best left for your doctor, but I can tell you this: Dr. Neil Nathan, a physician and mold expert in California, recommends stopping with any supplement that makes symptoms worse. His protocols are geared towards Candida and mycotoxins, but if something is making you sick, it’s likely a good idea to stop, or at a minimum, cut way way back on dosing. There is nothing wrong with taking 1/4 of a capsule, supplement doses are often arbitrary.

    • Guy says:

      I’ve read in “Grow a New Body” by Alberto Villoldo that you should be off of sugar and grains for 1 to 2 weeks before supplementing with S. Boullardii. You will have gas and bloating if you don’t!! Simple, but not easy!

    • Catsiber says:

      Tami, i also suffer from diarrhea loose stools. Started taking s boulardii today as because my gut is completely damaged from repeated antibiotics. Please tell me how are you now? How are you managing your problem.

  12. susie says:

    Hi, IBS-c sufferer here along with chronic yeast infections, arthritis, fibromyalgia.

    You mentioned something about alternating one week on and one week off of SB. Can I stay on it consistently for awhile to help with the candida overgrowth and my other problems?


  13. Kate Becker says:

    Hi there! Thanks for all the wonderful information! It this a good option to take to avoid yeast infections after a course of cipro? All the other benefits sound wonderful too!

    Thanks again,

  14. Carol says:

    I bought this type of probiotic because my son had diarrhea…I was wondering if I take it and I don’t have diarrhea would it constipate me?

    • Cynthia says:

      Hi Carol,

      I take have taken Florastor and also Jarrow Formulas that contain saccharomyces boulardii lyophilized and have not experienced any issues with constipation. I have yet to try the Spartan Strain by Gene Foods but hope to at some point.
      I hope this helps! 🙂

      • Rick says:

        Hi Cynthia,
        I recently started using Florastor and am curious to know if you experienced better or different results with Jarrow?

  15. Judy says:

    Is there a child’s chewable or a capsule that could be put into applesauce for one who won’t swallow pills that you would recommend?

      • Nelly says:

        Judy, my daughter is now taking S. Boulardii. Our naturopathic doctor prescribed the capsules and I break it open and pour it in her juice – she never noticed that she has been taking it.It is Saccharomyces Boulardii 100 caps by Kirkman Labs. I hope this helps.

  16. Terri says:

    So sorry to hear of your suffering- sadly, too many people have been in or are in similar ways. My experience became better by researching and education, finding awareness and learning to ask the right questions.
    Maybe try researching “The Infection Connection” with Dr. Nikolas Hedberg of N.C.
    Hedberg also has extensive research on healing Lyme disease, and it is in layman terms. He can also be found thru Hawthorne University webinars- Simpy search Dr. Nikolas Hedberg Hawthorne University-
    “The Infection Connection” “Lyme Disease” “Auto Immune Disease and Infection”.
    Dr. A. Vojandi has a great webinar on infections and autoimmune disease, much more technical.
    Barbara O’Neill of Misty Mountain Re-Treats of Australia has some great educational videos on how our bodies work and how to help us be healthy. Very easy to listen to and learn.

    Of course this is just information for you to research and learn by. Always be sure to follow the advise of your doctor.
    Hopefully, this information is useful to you in some way.
    God Bless you with a speedy recovery.

  17. Angie says:

    Please please help me, Ive been bedridden since 2014. Long story why…I have Lyme and co-infections. I was recently diagnosed with pneumonia I have had C. diff in the past. But now, to make matters worse, I was put on steroids in 2008 before I knew I had Lyme.

    When I had C. diff, I wasn’t on steroids, which as you know are immunosuppressants. My question for you is you said only good s. boulardii doesn’t need to be kept in the fridge. I have diarrhea now and can barely eat. I’m afraid I’m going to die. What s. boulardii brand doesn’t need kept in the refrigerator? That’s my main question. Please, I beg you please help me. If I catch it again I will die for sure. I have a son who is 12. I don’t want to leave him so I beg you what s. boulardii brand do you use. Every brand I have ever had ordered for me says to refrigerate. Thank you for your time.

    • Angie, I am so sorry to hear you’ve been suffering. To begin, these are all questions for your doctor, not for us, however, I can tell you that the best S. boulardii preparations are usually lypholized, meaning they’re freeze dried, and yes, do not need to be refrigerated. Thorne makes an excellent product and the Spartan Strain product on our site is top notch as well. I wish you good luck.

    • Chris says:

      I have c diff for 3 months, thought I might die as well. I am strong, healthy 33 male. Terrible Ilness. The antibiotic Vancomycin is the only thing to help me so far. Take this antibiotic, when your finished start taking probiotics. Call me if you want 1 403 463 6877.


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