Saccharomyces Boulardii

80 capsules



(ex. tax)
4.6/5 (11 reviews) Read verified product reviews

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Suitable for



Gluten free

Gluten free



Dairy free

Dairy free

GMO free

GMO free

See full ingredients list


This highly researched supplement from Optibac Probiotics provides 5 billion CFU of pure Saccharomyces boulardii, clinically trialled and shown to support gut health especially in those with occasional diarrhea*. 

saccharomyces boulardii press

Probiotic Strains

  • Saccharomyces boulardii
  • Product Description

  • How To Use

  • Ingredients

  • Help & Advice

  • Reviews

  • Delivery & Returns

  • Product Description

    A pure Saccharomyces boulardii supplement

    For those with occasional diarrhea*.

    Key benefits

    • Pure Saccharomyces boulardii probiotic – Optibac Saccharomyces boulardii contains 5 billion live cultures of pure S. boulardii, guaranteed until end of expiry
    • Digestive supplement – complements the natural gut bacteria and supports digestive health, including occasional diarrhea*
    • Internationally acclaimed – used around the world for 50 years, Saccharomyces boulardii is extremely well-researched 
    • Scientifically proven – shown in clinical trials to survive stomach acidity and reach the gut alive
    • Travel friendly - with no need for refrigeration, even in hot, humid environments, you can take this easy-to-swallow supplement with you wherever you go
    • Natural and vegan – vegan, gluten free for those with coeliac disease, and made with absolutely no artificial flavorings or colorings
    • Suitable for daily use – can be taken intensively or on a long-term basis
    • Saccharomyces boulardii UK – Optibac was the first brand to introduce S. boulardii to the UK 
    • Highly recommended – from the UK’s most trusted & recommended brand of friendly bacteria supplements, as determined in an independent survey of 1000 British women+

    Product reviews


    Customer feedback collected via independent review platform Trustpilot. See more Saccharomyces Boulardii reviews for more customer opinions collected via our own website.

  • How To Use

    Recommended use

    Natural dietary supplement suitable for adults and children (from 1 year onwards) with the following recommendations:

    • Take 1 capsule daily. May be increased up to 6 capsules daily as desired (depending on severity of symptoms), or as professionally directed.
    • For young children the use should be lowered. 1 capsule daily, may be increased up to 3 capsules daily.
    • If taking anti-fungals, take separately (at least 2 hours apart).
    • For those unable to swallow capsules, open and mix contents with a cool drink/food.

    Storage instructions

    • For best results, do not remove desiccant sachet from the glass jar and close lid firmly after each use.
    • Store in a cool, dry place below 25°C (77 °F) and out of direct sunlight.

    Customer Questions

    All questions answered by probiotic experts Dr Kate Stephens PhD (Food and Microbial Sciences) BSc(Hons) Medical Microbiology and Kerry Beeson BSc (Nut. Med.) Nutritional Therapist.

    Is Saccharomyces boulardii a well-known probiotic strain?

    Saccharomyces boulardii is an internationally acclaimed strain; in fact, it is one of the most highly researched probiotics in the world! The unusual thing about it, however, is that it is actually a yeast, rather than a type of bacteria, and is the only known yeast to be classed as a probiotic1. It has been used safely2,3 for over 50 years worldwide to support occasional diarrhoea4 and overall gut health*3,5.

    How many Saccharomyces boulardii capsules should I take a day?

    As we all have a unique gut microbiome and varying health priorities, the response to Saccharomyces boulardii is different for each individual. You can take up to a maximum of 6 capsules per day, but it is recommended to start with 1-2 capsules per day and build up from there as required. When taking a higher number of capsules (3-6 capsules) it is advised to spread these across the course of the day, though if you have a particularly upset stomach, you can take 3-4 capsules together initially.

    What time should I take Saccharomyces boulardii?

    There is no right or wrong time of the day to take Saccharomyces boulardii, so whenever fits in with your schedule is fine. This probiotic yeast is more robust to environmental stressors than more common bacterial probiotics, and shows strong resistance to heat, humidity, and stomach acidity levels. It doesn’t need to be refrigerated and can be taken with or without food.

    Can I take Saccharomyces boulardii alongside other probiotic supplements?

    Yes, and it is recommended to do so. Saccharomyces boulardii works differently to other probiotic supplements because this ‘friendly yeast’ does not colonize for long in the gut. On its way through the digestive tract, however, it has many positive effects*, helping to heal the delicate gut lining5 and displacing certain bad bacteria or unfriendly yeasts6.

    What makes Saccharomyces Boulardii suitable for travel?

    Saccharomyces boulardii is a resilient strain of yeast which survives well in hot and humid conditions7, making it great for travelling. It doesn't need to be refrigerated meaning you can take it with you wherever you travel around the world.


    Probiotics are not recommended for those with serious medical conditions e.g. those who are severely immunosuppressed, have pancreatitis, are in the ICU, have melaena, have a central venous catheter, short bowel syndrome, or patients with open wounds following major surgery; unless under a doctor's care. Keep out of reach of children.

    This is a dietary supplement and is not intended to prevent, treat or diagnose any medical conditions. Probiotic supplements should not be used as a substitute for a healthy diet and lifestyle. If you are taking any medications or have a serious medical condition, consult a doctor before use. Optibac supplements will not cause dependency and may be used on an ongoing basis.

    Pregnant or breastfeeding women should consult their doctor before taking Saccharomyces boulardii.


    1. Czerucka D, Piche T, Rampal P. Review article: yeast as probiotics -- Saccharomyces boulardii. Alimentary Pharmacology & Therapeutics. 2007 Sep;26(6):767-778. DOI: 10.1111/j.1365-2036.2007.03442.x.
    2. McFarland L.V., (2010), ‘Systematic review and meta-analysis of Saccharomyces boulardii in adult patients’. World Journal of Gastroenterology, 16(18):2202–2222.
    3. Kelesidis T, Pothoulakis C.(2012) ‘Efficacy and safety of the probiotic Saccharomyces boulardii for the prevention and therapy of gastrointestinal disorders’ Therapeutic Advances in Gastroenterology. 2012;5(2):111-125.
    4. Das S, et al. (2016) Efficacy and Safety of Saccharomyces boulardii in Acute Rotavirus Diarrhea: Double Blind Randomized Controlled Trial from a Developing Country. J Trop Pediatr. Dec;62(6):464-470
    5. Qamar et al., (2001), ‘Saccharomyces boulardii Stimulates Intestinal Immunoglobulin A Immune Response to Clostridium difficile Toxin A in Mice’. Infect. Immun., 69(4):2762–2765.
    6. Murzyn et al., (2010), ‘Capric Acid Secreted by S. boulardii Inhibits C. Albicans’. Plos One, 5(8): 

    7. Hossain M et al., (2020) Identification and Growth Characterization of a Novel Strain of Saccharomyces boulardii Isolated From Soya Paste. Frontiers in Nutrition, 2020; 7: 27.

  • Ingredients


    Probiotic cultures: Saccharomyces boulardii (275mg); hydroxypropyl methylcellulose

    Each capsule guarantees 5 billion CFU.

    saccharomyces boulardii supplement fact panel


    • Vegan
    • Vegetarian
    • Dairy free
    • Gluten free
    • Soy free
    • GMO free
    • No added sugars
    • Free from artificial flavorings, colorings and preservatives
    • No chemicals or parabens
  • Help & Advice

    Talk to our experts

    If you have a specific question or need some advice on which product to choose please email or click on the link below for our contact form

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  • Reviews

    Customer reviews

    • I am a big fan of Optibac probiotics I am a big fan of Optibac probiotics. They are consistently great quality & are always delivered well packaged & quickly. Highly recommended

      Nina - 2nd September 2021

    • I find Saccharomyces boulardii is excellent for preventing gut issues. Anytime my stomach starts complaining I make sure I add some of these to my probiotic routine and it stops the problem quickly.

      Eleanor Piper - 9th July 2021

    • Well, I thought that finding the everyday probiotic was a miracle in itself for helping with my diverticular disease, I then find miracle number 2. With my diverticular disease I can sometimes get breakthrough symptoms of diarrhoea and urgency. I used to take a high street brand of bunger uppers, the ones that melt in your mouth. Using the high street brand left me constipated for days and as anyone knows with diverticular disease, constipation is a no no as it can leave the bowel hoarding all sorts of nasty bacteria and especially in the little sacs of diverticulae and thereby leading to an infection forming and eventually leading to a course of antibiotics. I have become immune to one type of antibiotic already and therefore agree to take antibiotics with the greatest caution as I don't want to get some dreadful disease in the future and there aren't any antibiotics to cure me. Saccharomyces boulardii is a constant in my cupboard as just 1 capsule did the job of stopping the diarrhoea without harming the gut. There were no after-effects just fairly normal bowel movements again. As with the high street brand I could be constipated for up to a week! thanks again to optibac for their thorough research of their products. I actually rang the company and asked which particular product would be good for my problem. They were great and guided me to the right choice. thanks again dee x

      Dee Richardson - 29th May 2019

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  • Delivery & Returns

    USA Shipping

    Coronavirus Update

    We ship all USA orders from our warehouse in Hampshire in the UK. Due to the ongoing global pandemic many US, European and Worldwide postal routes are seeing increased transit times. Delivery times provided on this site are therefore a guide and not a guarantee. Express Services largely remain unaffected however these routes are typically subject to local tax and duties at customs.

    USA standard shipping: $4.99

    International postal order - typically deatched and delivered within 5-10 working days.
    Free standard shipping on orders over $100.

    USA express shipping: $6.99

    We use DHL and orders are typically dispatched and delivered within 2-5 working days.



    Good to know

    • We'll send you an email to confirm once your parcel has been dispatched.
    • For delivery queries, please email
    • We are unable to ship orders to PO boxes.
    • Product prices on this website are always shown in US dollars (USD $) and exclude tax - tax is not applicable as orders are fulfilled from the UK.

    Worldwide Delivery

    • We deliver to more than 50 countries.
    • Shipping is charged at cost - please note that duties may apply.
    • Please allow 3-7 working days for delivery within Europe and 5-12 days to all other destinations. Includes order tracking.  
    • If you are located within the United Kingdom or Europe, we recommended switching to our UK website.
    • International deliveries might currently take a little longer due to the global coronavirus situation. Please refer to the webpage of our international delivery provider DHL to confirm the number of days it takes to receive your order and whether they currently ship to your country.
    • Most international delivery prices are dependent on the size and weight of your order and where it is being sent. You'll be shown the final price of shipping in the checkout, before payment, once we have your address and order details.
    • Long distance shipping and short-term exposure to high temperatures will not compromise the viability of our products. Customers living in very hot countries should store the products out of direct sunlight and refrigerate if the option is available.

    For more details regarding international orders, currency conversion and applicable tax for orders outside the USA, please take a look at our delivery FAQ.