Probiotics

Saccharomyces boulardii

Also called: S. boulardii, probiotic yeast

A probiotic yeast.

Why people take it
Diarrhoea from antibiotics, travellers' diarrhoea.
What the evidence says
Good evidence for preventing antibiotic-related diarrhoea.
How it is usually taken
Usually 250 to 500 mg (5 to 10 billion CFU) once or twice a day; can be taken with antibiotics.
Be careful
Avoid with a central line or weak immunity (rare bloodstream infections).
Medicines it can interact with
Antifungals (fluconazole, nystatin) kill it; avoid with a central line or severe immune suppression.

Other probiotics

Lactobacillus rhamnosus GGBifidobacteriumKefirKombucha

Common questions

What is Saccharomyces boulardii?

A probiotic yeast.

Why do people take Saccharomyces boulardii?

Diarrhoea from antibiotics, travellers' diarrhoea.

Does Saccharomyces boulardii work?

Good evidence for preventing antibiotic-related diarrhoea.

How much Saccharomyces boulardii do people take?

Usually 250 to 500 mg (5 to 10 billion CFU) once or twice a day; can be taken with antibiotics.

Is Saccharomyces boulardii safe?

Avoid with a central line or weak immunity (rare bloodstream infections).

Does Saccharomyces boulardii interact with medicines?

Antifungals (fluconazole, nystatin) kill it; avoid with a central line or severe immune suppression.

Sources and further reading

Last reviewed 31 October 2026. Written by Satya Babu.

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