Saccharomyces boulardii (S. boulardii or S.B. for short, and pronounced Sack-a-row-my-sees boo-lar-dee), is a microorganism which differs greatly from the well-known probiotic species such as acidophilus. Saccharomyces boulardii is actually a natural yeast, originally extracted from the lychee fruit.

This microorganism is understood to be a transient; meaning that it passes through the system without binding to the gut wall lining (a sought-after feature in high quality probiotic bacteria). S. boulardii however has undergone years of rigorous clinical research demonstrating not only its safety, but its ability to bind to and flush out pathogens such as E. coli and Salmonella; thereby naturally supporting patient gut health in the case of diarrhoea. In fact, research on Saccharomyces boulardii is so extensive, that this strain is registered as a medicine in over 100 countries. S. boulardii has also been shown to have considerable anti-inflammatory properties, helping to maintain gut health in those with Inflammatory Bowel Disease and Irritable Bowel Syndrome. It has furthermore been shown to help clear overgrowth of pathogenic yeasts such as Candida albicans.

OptiBac Probiotics is the only UK company to do a pure Saccharomyces boulardii supplement (which contains 5 billion pure micro-organisms per capsule) and can be found here.

Saccharomyces boulardii can also be found in our supplement For travelling abroad ( which contains 1 billion micro organisms per capsule, combined with other probiotic species.)

Microscopic image of S. boulardii microorganisms.

In terms of cost per billion microorganisms, Saccharomyces boulardii by OptiBac Probiotics is the best value supplement containing S. boulardii currently available in the UK. To read more about S. boulardii from OptiBac Probiotics, so that you can recommend it with confidence, click here.

The name

Saccharomyces boulardii lends its name to the French scientist, Henri Boulard, who discovered the probiotic yeast in 1923 in South East Asia where he noticed people using the skin of lychee fruit for its beneficial health properties. S. boulardii is often referred to as S. boulardii lyo, where the 'lyo' is short for 'lyophilisation' - a form of freeze-drying which S. boulardii normally undergoes in its supplement form. This process allows the supplement to be shelf-stable so that refrigeration is not necessary. OptiBac Probiotics Saccharomyces boulardii is lyophilised.

For more information on the classification of Saccharomyces boulardii, please read our in-depth article.