Saccharomyces boulardii probiotic for the gut microbiota

Saccharomyces Boulardii is a supplement containing a non-pathogenic yeast resistant to stomach acids and proteolysis.

The concept of incorporating microorganisms into the human diet dates back several thousand years: today, traditional fermented milks and supplements containing live microorganisms are consumed all over the world by people keen to improve their health.

What exactly is the yeast Saccharomyces Boulardii?

Saccharomyces boulardii is a natural-source yeast, first isolated from lychee and mangosteen peel by the French microbiologist Henri Boulard at the beginning of the 20th century. It is now sold in almost 200 countries under various brand names, the best-known being ‘Ultra Levure’.

A healthy gut microbiota is a “complex, balanced collection of microorganisms which normally live in the gastrointestinal (GI) tract and which fulfil a role in the host’s nutrition, physiology and immune system control” (1). Environmental factors (smoking, antibiotics, intense stress, poor diet) can upset the balance of this flora, potentially allowing certain pathogenic bacteria to spread and cause damage.

Though not naturally present in human microbial flora, Saccharomyces Boulardii is able to grow there. It can rapidly reach high concentrations in the GI tract and remain there for several days. Once supplementation stops, Saccharomyces boulardii is gradually eliminated within 2 to 4 days in stools (2).

How does it act in the body?

Saccharomyces Boulardii is able to synthesise proteins in response to the various types of stress it encounters, in order to adapt to its environment. Stomach acids encourage it, in particular, to produce heat shock proteins (3) and various factors (more than 1500 have been identified) able to influence certain of the body’s functions and correlated with various mechanisms of action (Buts & De Keyser, 2006).

Five good reasons to choose the supplement Saccharomyces Boulardii

1. It survives stomach acidity (because of its optimal pH of between 4.5 and 6.5) and proteolysis (digestion of food) very well (4).
2. It can be taken at the same time as antibiotics because, as a yeast microbe, it is resistant to them.
3. Its optimal temperature of 37° C enables it to survive in the body, unlike its related strain Saccharomyces cerevisiae (5).
4. It contains 20 billion CFU (the unit used to estimate the amount of viable fungal cells) per dose.
5. It contains no synthetic additives – likely to upset the microflora – which is not the case for most Saccharomyces Boulardii supplements and medicines.