Another Name for Saccharomyces boulardii: Scientific Name, Synonyms, and Common Terms

If you are searching for another name for Saccharomyces boulardii, you may have noticed that this probiotic yeast appears under several different names in scientific papers, supplement labels, and medical references.

The most important alternative is Saccharomyces cerevisiae var. boulardii, although the exact naming and classification can vary between sources.

Some references also use S. boulardii, S. cerevisiae boulardii, or strain-specific designations such as Saccharomyces boulardii CNCM I-745.

The naming can be confusing because its taxonomic position has been debated. Historically, it was treated as its own species, while later genetic research placed it within the Saccharomyces cerevisiae group.

NCBI currently lists Saccharomyces boulardii as an invalid synonym under Saccharomyces cerevisiae.

This guide explains the names you may encounter, what they mean, and which terms should not be treated as exact synonyms.

The Most Common Alternative Name for Saccharomyces boulardii

The name most often used as an alternative is Saccharomyces cerevisiae var. boulardii.

This terminology reflects the classification of the organism as a particular variety within Saccharomyces cerevisiae. Scientific literature has described the probiotic as closely related to S. cerevisiae, with modern genetic evidence supporting its placement within that species.

Here are the main names and forms you may encounter:

• Saccharomyces cerevisiae var. boulardii — a taxonomic name used in scientific literature.
• Saccharomyces boulardii — the traditional and widely recognized name.
• S. boulardii — abbreviated form of the traditional name.
• S. cerevisiae var. boulardii — shortened form of the variety designation.
• Saccharomyces cerevisiae boulardii — a less formal naming style found in some references.
• S. cerevisiae boulardii — abbreviated version of that terminology.
• Saccharomyces boulardii CNCM I-745 — a designation referring to a specific probiotic strain.
• S. boulardii CNCM I-745 — shortened strain notation.
• Probiotic Saccharomyces yeast — a descriptive term rather than a formal scientific synonym.
• Probiotic yeast — a broad common description used because it is a yeast used as a probiotic.

Not all of these terms have exactly the same taxonomic status. Some are synonyms, some are abbreviations, and others describe the organism or identify a particular strain.

Scientific Names and Taxonomic Terms Related to Saccharomyces boulardii

Understanding the scientific naming system makes the different terms much easier to recognize.

The word Saccharomyces identifies the genus. Cerevisiae identifies the species. Boulardii is associated with the probiotic variety or historical species name.

Important terms include:

• Saccharomyces — the genus containing this yeast.
• Saccharomyces cerevisiae — the species with which S. boulardii is now closely associated.
• Saccharomyces cerevisiae var. boulardii — a commonly used variety designation.
• Saccharomyces boulardii — the traditional name.
• S. boulardii — abbreviated traditional name.
• S. cerevisiae — abbreviated species name.
• S. cerevisiae var. boulardii — abbreviated variety name.
• Saccharomycetaceae — the fungal family containing the Saccharomyces genus.
• Saccharomycetales — the order that includes Saccharomycetaceae.
• Saccharomycetes — the class containing this group of yeasts.

These are not all interchangeable names. For example, Saccharomyces is a genus, while Saccharomycetaceae is a family. They help describe where the organism fits in biological classification.

NCBI places Saccharomyces cerevisiae within Eukaryota, Fungi, Ascomycota, Saccharomycetes, Saccharomycetales, Saccharomycetaceae, and Saccharomyces.

Names You May See on Probiotic Supplements

A supplement label may use a shorter name than a scientific paper. This can make the same organism look like a completely different ingredient.

Common label terminology includes:

• Saccharomyces boulardii
• S. boulardii
• Saccharomyces cerevisiae var. boulardii
• S. cerevisiae var. boulardii
• S. boulardii CNCM I-745
• Saccharomyces boulardii CNCM I-745
• Boulardii yeast
• Probiotic yeast
• Saccharomyces probiotic
• Boulardii probiotic

The exact wording matters. A product that simply says Saccharomyces yeast may not identify the same strain or preparation as a product specifically labeled S. boulardii CNCM I-745.

That distinction is useful because probiotic research is often strain-specific. One study may investigate one strain, while another product contains a different strain of the same broader organism.

For that reason, it is better to look for the full strain designation when comparing probiotic products rather than relying only on the word Saccharomyces.

Older Names for Saccharomyces boulardii

The history of this yeast helps explain why multiple names still appear today.

Saccharomyces boulardii was originally described as a separate species. Later genetic studies found that it is extremely closely related to Saccharomyces cerevisiae. Some scientific sources therefore began treating it as a variety or strain of S. cerevisiae rather than as a completely separate species.

Historical and related terminology includes:

• Saccharomyces boulardii
• S. boulardii
• Saccharomyces cerevisiae var. boulardii
• S. cerevisiae var. boulardii
• Saccharomyces cerevisiae boulardii
• S. cerevisiae boulardii
• Boulard’s yeast
• Boulardii yeast
• Probiotic Saccharomyces
• Probiotic Saccharomyces yeast

The phrase Boulard’s yeast is descriptive and refers to Henri Boulard, who is associated with the discovery of the organism. It should not be confused with a separate species.

Strain Names Associated With This Probiotic Yeast

A major source of confusion is the difference between a species name and a strain designation.

For example, CNCM I-745 identifies a particular strain used in probiotic research and products. It is more specific than simply saying Saccharomyces boulardii.

Related terminology includes:

• CNCM I-745
• S. boulardii CNCM I-745
• Saccharomyces boulardii CNCM I-745
• S. cerevisiae var. boulardii CNCM I-745
• Probiotic strain CNCM I-745
• Boulardii CNCM I-745
• S. boulardii strain
• Boulardii strain
• Probiotic yeast strain
• Saccharomyces probiotic strain

A strain name should not automatically be treated as a synonym for the entire species or group.

This is especially important when reading research. A finding involving one specific strain cannot necessarily be applied to every Saccharomyces product. Research reviews have noted that many studies have focused on particular strains, including CNCM I-745.

Common Abbreviations for Saccharomyces boulardii

Scientific writing often shortens names after introducing them once.

You may see these abbreviations:

• S. boulardii
• S. boulardii
• Sb
• S. cerevisiae var. boulardii
• S. cerevisiae boulardii
• S. cerevisiae
• Sc
• Sb CNCM I-745
• S. boulardii CNCM I-745
• S. cerevisiae var. boulardii CNCM I-745

The abbreviations Sb and Sc are sometimes used in scientific publications to distinguish S. boulardii from S. cerevisiae. However, abbreviations can vary between authors, so the surrounding text should always be checked.

The simplest abbreviation for everyday reading is usually S. boulardii.

Is Saccharomyces boulardii the Same as Saccharomyces cerevisiae?

This is one of the most common questions about the organism.

The answer depends on whether you are discussing historical naming or modern taxonomic classification.

Historically, Saccharomyces boulardii was treated as a separate species. More recent genetic research has shown that it is extremely closely related to Saccharomyces cerevisiae. Several scientific sources classify it within S. cerevisiae, often using the designation Saccharomyces cerevisiae var. boulardii.

At the same time, the traditional name Saccharomyces boulardii remains widely used, particularly in clinical and probiotic contexts.

This is why you may see both names in reputable literature.

A useful way to understand the relationship is:

Term	What it generally means
Saccharomyces	Genus
Saccharomyces cerevisiae	Species
Saccharomyces boulardii	Traditional name
S. cerevisiae var. boulardii	Variety-style classification
CNCM I-745	Specific strain designation
S. boulardii	Abbreviated traditional name
Probiotic yeast	Descriptive term
Boulardii yeast	Common descriptive name

The important point is that Saccharomyces boulardii should not simply be treated as an unrelated yeast species separate from S. cerevisiae.

Terms That Should Not Be Used as Exact Synonyms

Search results can sometimes make related yeast names appear interchangeable. They are not.

The following terms should be treated carefully:

• Baker’s yeast — usually refers to Saccharomyces cerevisiae, not specifically the probiotic strain.
• Brewer’s yeast — commonly refers to S. cerevisiae used in brewing.
• Saccharomyces cerevisiae — a broader species name, not necessarily a specific boulardii preparation.
• Saccharomyces — a genus containing multiple species.
• Probiotic yeast — a broad descriptive category.
• Fermentation yeast — a functional description, not an exact synonym.
• Yeast probiotic — a category rather than a taxonomic name.
• Saccharomyces probiotic — descriptive rather than a complete scientific designation.
• Baker yeast — another common term for baking strains of S. cerevisiae.
• Brewer’s yeast — not a precise substitute for S. boulardii.

NCBI lists Saccharomyces boulardii as an invalid synonym under Saccharomyces cerevisiae, while also listing common names such as baker’s yeast and brewer’s yeast for S. cerevisiae. That does not mean every baker’s or brewer’s yeast product is the same as a probiotic S. boulardii strain.

This distinction is important when reading supplement labels.

What Does Saccharomyces Boulardii Mean?

The name Saccharomyces boulardii refers to a probiotic yeast rather than a bacterial probiotic.

Unlike many familiar probiotics, which are bacteria, S. boulardii belongs to the fungi and yeast group. It is associated with the genus Saccharomyces. Medical literature has described it as a probiotic yeast used in research involving gastrointestinal conditions.

The word Saccharomyces comes from Greek roots associated with sugar and fungus or mold, reflecting the group’s relationship with sugar fermentation.

The word boulardii honors Henri Boulard, the microbiologist associated with its discovery.

So the name is not a nickname in the ordinary sense. It is a scientific designation with a historical background.

Why Are There Different Names for the Same Probiotic?

Scientific names change as researchers learn more about an organism.

Older classification methods relied heavily on visible characteristics and laboratory behavior. Modern taxonomy can use genetic and genomic information to compare organisms in much greater detail.

Research on S. boulardii found very high genetic similarity with S. cerevisiae. A genome study reported more than 99% genomic relatedness between the two groups and concluded that the probiotic strains belong within the S. cerevisiae species.

That history explains why both older and newer names continue to appear.

You might therefore encounter:

• Historical species name
• Modern variety designation
• Short scientific abbreviation
• Strain designation
• Product label terminology
• Clinical terminology
• Probiotic terminology
• Taxonomic terminology
• Common descriptive terms
• Research abbreviations

These terms can refer to the same general probiotic organism while communicating different levels of detail.

How to Tell Which Name a Product Uses

If you are looking at a probiotic supplement, start with the ingredient panel rather than relying on the front of the package.

Look for details such as:

• Saccharomyces boulardii
• S. boulardii
• Saccharomyces cerevisiae var. boulardii
• S. boulardii CNCM I-745
• Strain designation
• Number of viable cells
• Specific strain information
• Probiotic yeast
• Saccharomyces species
• Full scientific name

A label that provides a strain designation gives you more information than one that simply says Saccharomyces.

If you are trying to match a supplement to a particular research study, the strain designation is especially useful. Two products can contain related organisms but still differ in strain.

It is also wise to avoid assuming that all products containing S. cerevisiae are equivalent to products specifically containing S. boulardii.

Saccharomyces Boulardii vs. Saccharomyces cerevisiae

These names are closely connected but should not be used carelessly.

Saccharomyces cerevisiae is the established species name. It includes many strains used in areas such as baking, brewing, fermentation, research, and biotechnology.

Saccharomyces boulardii is the traditional name used for a particular probiotic yeast lineage. Modern literature often places it within S. cerevisiae, while the traditional name remains common in healthcare and probiotic discussions.

A simple comparison looks like this:

Name	Meaning
Saccharomyces cerevisiae	Established species name
Saccharomyces boulardii	Traditional probiotic yeast name
S. cerevisiae var. boulardii	Variety-style classification
S. boulardii	Abbreviated traditional name
CNCM I-745	Specific strain designation
Probiotic yeast	General description

This is why searching for an alternative name can produce several different answers.

Is S. boulardii a Bacteria or a Yeast?

S. boulardii is a yeast, not a bacterium.

It belongs to the fungal kingdom and the genus Saccharomyces. This makes it different from bacterial probiotics such as Lactobacillus and Bifidobacterium.

That difference matters because the biological characteristics of yeast and bacteria are not identical.

For someone reading a supplement label, the easiest terms to remember are:

• Yeast probiotic
• Probiotic yeast
• Saccharomyces yeast
• Boulardii yeast
• Saccharomyces probiotic
• S. boulardii
• Saccharomyces boulardii
• S. cerevisiae var. boulardii
• Saccharomyces cerevisiae boulardii
• Boulardii strain

Of these, only some are formal scientific designations. The others are useful descriptive terms.

What Is the Best Name to Use?

1.For general writing, Saccharomyces boulardii remains the clearest and most recognizable term.

2.For scientific or taxonomic discussion, Saccharomyces cerevisiae var. boulardii may be more appropriate depending on the classification system and source.

3.For a specific probiotic preparation, use the strain designation, such as CNCM I-745, when that is the strain being discussed.

A practical approach is:

• Use Saccharomyces boulardii for general readers.
• Use S. boulardii after the full name has been introduced.
• Use Saccharomyces cerevisiae var. boulardii when discussing its classification.
• Use CNCM I-745 when referring specifically to that strain.
• Use probiotic yeast when a simple descriptive phrase is enough.
• Avoid calling every S. cerevisiae product S. boulardii.
• Avoid treating baker’s yeast and brewer’s yeast as exact equivalents.
• Check the strain when comparing scientific studies.
• Use the full name when precision matters.
• Remember that scientific classification can change as evidence develops.

Quick Reference for Alternative Names

If you only need a short answer, these are the most useful terms to recognize:

Name or term	Use
Saccharomyces boulardii	Traditional and widely recognized name
S. boulardii	Short scientific form
Saccharomyces cerevisiae var. boulardii	Variety-style taxonomic name
S. cerevisiae var. boulardii	Abbreviated variety name
Saccharomyces cerevisiae boulardii	Alternate naming style
S. cerevisiae boulardii	Abbreviated form
S. boulardii CNCM I-745	Specific strain designation
Boulardii yeast	Descriptive common term
Probiotic yeast	General description
Saccharomyces probiotic	General probiotic description

The first three are the most important if your goal is to understand the scientific terminology.

FAQs:

What is another name for Saccharomyces boulardii?

One of the main alternative names is Saccharomyces cerevisiae var. boulardii. You may also see S. boulardii, S. cerevisiae boulardii, or the strain-specific name S. boulardii CNCM I-745. The exact terminology depends on whether the source is discussing taxonomy, clinical use, or a specific strain.

Is Saccharomyces cerevisiae var. boulardii the same as Saccharomyces boulardii?

They refer to the same general probiotic yeast lineage, but the names reflect different approaches to classification. Saccharomyces boulardii was historically treated as a separate species, while later genetic research supported placing it within Saccharomyces cerevisiae.

Is Saccharomyces boulardii a type of yeast?

Yes. Saccharomyces boulardii is a probiotic yeast. It belongs to the genus Saccharomyces and is classified within the fungal kingdom.

Is Saccharomyces boulardii the same as baker’s yeast?

Not exactly. Baker’s yeast generally refers to Saccharomyces cerevisiae strains used for baking. S. boulardii is a particular probiotic lineage associated with S. cerevisiae. Although they are closely related, baker’s yeast should not automatically be considered equivalent to a S. boulardii probiotic.

What does CNCM I-745 mean?

CNCM I-745 is a strain designation associated with a specific Saccharomyces boulardii probiotic strain. It provides more precise identification than simply saying S. boulardii. Research involving a particular strain should not automatically be assumed to apply identically to every Saccharomyces product.

Why does Saccharomyces boulardii have more than one scientific name?

Its naming changed as scientific understanding of its genetics and relationship to Saccharomyces cerevisiae developed. It was originally described as a separate species, but later genetic studies supported its placement within S. cerevisiae. The older name remains widely used.

Can I use S. boulardii as a shorter name?

Yes. S. boulardii is a common abbreviation of Saccharomyces boulardii. In formal writing, it is best to write the complete name the first time and then use the abbreviation afterward.

What is the simplest name for Saccharomyces boulardii?

For most readers, Saccharomyces boulardii is the simplest and clearest name. If you need a descriptive phrase, probiotic yeast also communicates what it is, although that phrase is broader and is not an exact scientific synonym.

Conclusions:

The search for another name for Saccharomyces boulardii can be confusing because this probiotic yeast has a history of changing taxonomic terminology.

The name Saccharomyces boulardii remains widely recognized, while Saccharomyces cerevisiae var. boulardii is an important alternative classification.

You may also encounter S. boulardii, S. cerevisiae boulardii, and strain-specific terms such as CNCM I-745.

The key is to understand the difference between a true scientific name, an abbreviation, a descriptive term, and a strain designation.

Once that distinction is clear, most labels and scientific references become much easier to understand.