Saccharomyces boulardii

What is Saccharomyces boulardii?

Saccharomyces boulardii is a yeast, known in full as Saccharomyces cerevisiae var. boulardii. That makes it different from most probiotics on the shelf, which are lactic acid bacteria such as Lactobacillus and Bifidobacterium. Because it is a yeast and not a bacterium, many manufacturers state on the pack that it can be taken alongside other probiotic products.

The amount is given in CFU (colony-forming units), usually in billions per capsule. That figure is the main way to compare one product with another.

Our range

• NOW Foods Saccharomyces Boulardii – capsules with a stated CFU count per serving.
• Swanson Saccharomyces Boulardii – a straightforward capsule product.
• Cytoplan Saccharomyces Boulardii – from the British brand Cytoplan.
• Jarrow Formulas Saccharomyces Boulardii + MOS – the yeast combined with MOS (mannan-oligosaccharides), a carbohydrate obtained from yeast cell walls.

What to look for on the label

• CFU at expiry or at manufacture: live cultures decline over time. A count guaranteed until the best-before date tells you more than the figure at the time of production.
• Storage: some products are shelf-stable, others should be kept in the fridge. Check the pack after delivery and store it as stated.
• Capsule: many capsules are vegetable cellulose, so the product may suit a vegan diet – the label says whether it does.
• Extras: plain S. boulardii or a blend, for example with MOS.
• Dose: follow the directions on the label.

Food supplements are not a substitute for a varied diet. If you take medicines or are pregnant, ask your doctor first.

Frequently asked questions

Is Saccharomyces boulardii a bacterium?

No. It is a yeast from the Saccharomyces family. Most other probiotics are bacteria, which is why S. boulardii is often listed as a separate group.

Can I combine it with other probiotics?

Many manufacturers say that it can be taken together with bacterial probiotics. Read the directions of both products and follow them.

Does it need to be kept in the fridge?

That depends on the product. Some capsules are stable at room temperature, others are meant to be kept chilled. The label tells you which applies.