Saccharomyces boulardii is a well-researched, internationally acclaimed strain, proven to survive through stomach acidity to reach the gut alive 5 billion live cultures per capsule, guaranteed until end of expiry Friendly yeast, more robust to environmental stressors than common bacterial live cultures, and especially stable and resistant to heat and humidity No refrigeration required, contrary to some other live cultures supplements Used safely for over 50 years, suitable for vegans and vegetarians, and gluten free for those with coeliac disease or an intolerance All OptiBac strains are thoroughly researched and documented, so you can be confident you are getting the best OptiBac 'Saccharomyces boulardii' has been created especially for those seeking a natural option. It contains the internationally acclaimed strain of Saccharomyces boulardii in a pure supplement, with no additives or fillers. This well-researched and unique strain has been used safely around the world for over 50 years. Suggested for daily use, each capsule provides 5 billion live microorganisms that will survive through stomach acidity and reach the gut alive. This friendly yeast is more robust to environmental stressors than more common bacterial live cultures, and shows strong resistance to heat, humidity and stomach acidity levels. These live cultures of S. boulardii have been tested and shown to be especially stable and resistant. Saccharomyces boulardii is a natural and safe microorganism with vast scientific research and documentation. This strain has been internationally acclaimed as a well-researched and unique microorganism, and has been safely used for the last 50 years. Saccharomyces boulardii is a natural food supplement, and not a medicine, and is a unique microorganism which is sold widely in the US, Scandinavia, Germany & France. OptiBac specialise in live cultures and were the first UK company to make a pure Saccharomyces boulardii supplement. In terms of cost per billion microorganisms, the OptiBac Saccharomyces boulardii supplement is the best value supplement currently available in the UK. Saccharomyces boulardii can also be found in our supplement 'For travelling abroad' (which contains 1 billion micro organisms per capsule, combined with other live cultures).