Saccharomyces Boulardii

80 capsules |up to 80 days' supply

4.6/5 (11 reviews) Read verified product reviews
4.6/5 (11 reviews) Read verified product reviews
Dr Sasivimol Ahmed PhD, PG Dip (Personalised Nutrition), BSc (Food Science)
Recommended often, Saccharomyces boulardii is a friendly yeast and has been used safely around the world for over 50 years.
Dr Sasivimol Ahmed
Dr Sasivimol Ahmed PhD, PG Dip (Personalised Nutrition), BSc (Food Science)

Who is it for?

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.

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  • Vegan


  • Dairy free

    Dairy free

  • Gluten free

    Gluten free

  • Soy free

    Soy free

  • GMO free

    GMO free

Key benefits

A pure Saccharomyces boulardii supplement

For those with occasional diarrhea*.

  • 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 probiotic supplements.

Probiotic strains

  • Saccharomyces boulardii
See full ingredients list

General digestive


Complements gut bacteria

Customer reviews

4.6/5 (11 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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Help & advice

Speak to our team of experts (nutritionists, microbiologists and nutritional therapists) any time for free advice, with absolutely no obligation to buy.

Camilla Gray
Camilla Gray DipCNM Nutritional Therapist
  • How to use

  • Ingredients

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  • Delivery & returns

  • 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.!


    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.

    Gut health supplements are not intended to prevent, treat or diagnose any medical conditions. If taking probiotic supplements for gut health, note that these should not be used as a substitute for a varied and balanced diet and a healthy 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

  • 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
    Format Capsule
    CFU 5 billion
    Recommended Use 1 capsule daily
    Age Range Adult
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  • Delivery & returns

    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.


    If you have changed your mind, you can return goods, at your cost, unopened within 14 days for refund or exchange, this does not affect your statutory rights.

Customer Questions

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

Yes, Saccharomyces boulardii is one of the most highly researched probiotics in the world! But it’s actually a friendly yeast, not a type of bacteria. This internationally acclaimed probiotic has been used safely(1,2) for over 50 years worldwide but it was Optibac that first introduced Saccharomyces boulardii to the UK market. It is used to support occasional diarrhoea(3) and overall gut health*(4,5).

(1). Czerucka D, Piche T, Rampal P. Review: 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).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 (4). 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):111-1255.(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.
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S. boulardii has a broad range of potential benefits. It has been extensively researched and used worldwide for occasional diarrhoea. It has also been shown to promote a healthy gut environment, which encourages the growth of other good bacteria and discourages the growth of undesirable micro-organisms.

Each gut microbiome is unique, so the response to Saccharomyces boulardii will vary. Optibac Probiotics S. Boulardii supplement contains 5 billion live cultures per capsule. Try 1-2 capsules initially (or 3-4 capsules together if a stronger dose is required) and increase up to a maximum of 6 capsules (30 billion live cultures) spread over the day. Within these guidelines, then take as much or as little as you need, on an ad hoc or ongoing basis to support gut health and occasional diarrhoea(1,2).*

(1). 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(2). Zengbin L et al., (2021) Which Probiotic Is the Most Effective for Treating Acute Diarrhea in Children? A Bayesian Network Meta-Analysis of Randomized Controlled Trials. Nutrients, 13: 4319.
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It’s easy to take S. boulardii probiotic supplements – they can be taken at any time of day, with or without food! This friendly yeast is more robust than bacteria, and can resist high heat, humidity, and stomach acid levels(1). So it doesn’t need refrigeration, so you can take it with you, wherever you go.

(1). 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.
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Yes! In fact, it’s highly recommended. S. boulardii probiotic yeasts do not colonize for long in the gut but they harmonise well with good bacteria. They displace bad bacteria and unfriendly yeasts(1) and create a healthy gut environment in which good bacteria can flourish (2).For this reason, most people take them in combination.

(1). Murzyn et al., (2010), ‘Capric Acid Secreted by S. boulardii Inhibits C. Albicans’. Plos One, 5(8): (2). 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.
Read More

As a probiotic yeast, Saccharomyces boulardii is hardier than most good bacteria. It survives well in very hot or humid conditions(1), doesn’t require refrigeration and can be taken with or without food. It’s the perfect ‘friend’ to take on your worldwide travels!

(1). 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.
Read More

As it’s very good at slowing down stool transit time, at higher doses S. boulardii may cause mild constipation in certain individuals. If you tend to suffer with slow regularity,peak to your doctor or health professional for advice.

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