Saccharomyces Boulardii

40 capsules


(inc. VAT) was: £15.99
4.6/5 (72 reviews) Read verified product reviews

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Gluten free

Gluten free

No dairy

No dairy

See full ingredients list

Who is it for?

With 5 billion live cultures per capsule, this is for anyone looking to purchase a pure Saccharomyces boulardii supplement —an extensively researched, unique friendly yeast proven to reach the gut alive.

saccharomyces boulardii press

Optibac Probiotics Strains

  • Saccharomyces boulardii
  • Product Description

  • How To Use

  • Ingredients

  • Help & Advice

  • Reviews

  • Delivery & Returns

  • Product Description

    Who is Optibac Saccharomyces Boulardii for?

    For those wanting to take a pure Saccharomyces boulardii supplement.

    Key benefits

    • Each capsule contains 5 billion live cultures of pure Saccharomyces boulardii guaranteed until end of expiry
    • Saccharomyces boulardii is an extremely well-researched, internationally acclaimed friendly yeast
    • It has been used safely around the world for over 50 years
    • Scientifically proven to pass through stomach acidity and survive to reach the gut
    • Complements your natural gut bacteria
    • Easy to take on the go – no refrigeration required
    • Suitable from 1 year onwards
    • Can be used intensively or on an ongoing basis
    • As featured in Women's Health, and highly praised in TripAdvisor forums, Optibac first introduced Saccharomyces boulardii to the U.K. 
    • From the UK’s most trusted & recommended brand of friendly bacteria supplements. As determined in an independent survey of 1000 British women+.

    Available in three pack sizes of 16, 40 or 80 capsules.

    Now dispatching in our new look!

    We are introducing new, eco-conscious packaging this year, and the new designs will update gradually from product to product to minimise any waste. Please bear with us as you may receive orders with both current and new packaging over the coming months. We hope you like the new look!

    We’ve reduced the plastic in this packaging by 96%. We no longer use plastic containers.

    Update July 2021: The full name for this supplement is Optibac Saccharomyces boulardii though this is shortened to S. Boulardii on the front of the packaging. It was formerly called ‘For bowel calm’ outside of the EU.

    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 food 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 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 friendly bacteria strain?

    Saccharomyces boulardii is an internationally acclaimed strain; in fact, it is one of the most highly researched strains in the world! The unusual thing about it, however, is that it is actually a yeast, rather than a type of bacteria. Optibac first introduced Saccharomyces boulardii to the UK, but it has been used safely1,2  for over 50 years in countries around the world and has been used in numerous clinical trials.

    How many Saccharomyces Boulardii capsules should I take a day?

    As we all have a unique gut microbiome, 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 desired 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 strain of yeast is more robust to environmental stressors than more common bacterial live cultures, 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 friendly bacteria supplements?

    Yes, it is fine to take Saccharomyces Boulardii alongside your other live cultures supplements, in fact it is recommended to do so. Saccharomyces Boulardii works differently to other friendly bacteria supplements because it is a ‘friendly yeast’3 and does not colonise for long in the gut, but it works well with other live cultures supplements, so most people take it alongside.


    Live cultures 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 food 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. McFarland L.V., (2010), ‘Systematic review and meta-analysis of Saccharomyces boulardii in adult patients’. World Journal of Gastroenterology, 16(18):2202–2222.
    2. 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.
    3. 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.

  • Ingredients


    • Live cultures: Saccharomyces boulardii (275mg)
    • Vegetarian capsule: hydroxypropyl methylcellulose

    Each capsule guarantees 5 billion live cultures.


    • Vegan
    • Vegetarian
    • No dairy
    • Gluten free
    • Soy free
    • No added sugars
    • Free from artificial flavourings, colourings and preservatives
    • No chemicals or parabens
    • GMO free
  • Help & Advice

    Talk to our experts

    If you have a specific question or need some advice on which product to choose please contact our Nutrition Team on +44 (0) 1264 318 881 or click on the link below for our contact form.

    Need help choosing a product?
  • Reviews

    Customer reviews

    • I have tried other probiotics but I have found Optibac S. Boulardii suits me very well and I can tell the effect even on the improvement in my skin. Customer service couldn’t have been more courteous and helpful when I emailed about a question I had.

      Mrs Judy Morris - 9th November 2021

    • 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 had left a review earlier stating that this S. Boulardii product caused some uncomfortable side effects, and customer service responded very quickly. They have been very friendly and attentive to me, and I really appreciate it.

      Courtney - 28th July 2021

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  • Delivery & Returns


    Free UK Delivery over £40 

    Free standard UK delivery is automatically applied at the checkout when you spend £40.

    Standard 2nd class (Tracked): £2.50

    Allow 4-10 working days (Monday - Friday) for delivery; no deliveries on Saturdays

    1st class (Tracked): £3.95

    Allow 1-3 working days (Monday - Friday) for delivery; no deliveries on Saturdays

    Express Next Day (Tracked): £6.50

    Order before 2pm for guaranteed next working day delivery to most of the UK*. Orders placed on Friday will be delivered on Monday (next working day). Requires signature.
    *Express delivery may exclude the Channel Islands, Herm Island, Isle of Man, Isle of Wight, Northern Irish postcodes BT18 & upwards, Sark, Scottish borders and offshore and a small number of remote mainland destinations as determined by our delivery courier. 

    Good to know

    • We'll send you an email to confirm once your parcel has been dispatched.
    • For delivery queries, please call us on +44 (0)1264 339 770 or email
    • Orders placed before 2pm will be dispatched on the same working day.
    • Delivery within the UK and Northern Ireland has a fixed price, regardless of the size and weight of your order. 
    • Delivery times are estimates and not guaranteed unless otherwise stated.



    International Delivery

    We offer an excellent worldwide delivery service. For more details, please take a look at our delivery FAQ.

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