Saccharomyces Boulardii
IOH Nutrition — Gut Resilience
Saccharomyces Boulardii
A probiotic yeast, not a probiotic bacterium. That one difference is why it survives the trip, and why antibacterial antibiotics leave it alone.
10 Billion CFU per serving
1 organism, fully disclosed
60 vegetarian capsules
30 servings per bottle
Shelf stable — no refrigeration required
Why this one is different
Most probiotics are bacteria. This one is a yeast.
That is not a technicality. It changes what the organism has to survive on the way down, what it does while it is there, and what happens to it when you swallow a course of antibacterial medication.
A bacterial probiotic has a hard job. It has to survive stomach acid, then bile, then a warm and crowded environment already occupied by trillions of resident organisms. Then it has to arrive in enough numbers to matter. Manufacturers spend a great deal of engineering on that problem — enteric coatings, delayed-release shells, refrigeration, microencapsulation — because the organism itself is fragile.
Saccharomyces boulardii approaches the same trip from a different direction. It is a yeast. Yeast cell walls are structurally different from bacterial cell walls, which is why this organism is characteristically acid tolerant and heat tolerant, and why it does not need a cold chain to stay viable on a shelf. It is also the reason antibacterial antibiotics do not act on it — those drugs are built to target bacterial machinery, and a yeast simply is not the target.
Straight talk before we go further
S. boulardii does not permanently colonize you. It is transient. It reaches steady levels in the colon within roughly three days of consistent use, works while it is passing through, and is cleared within a few days after you stop. We think that is a feature, not a flaw — but you should know it, because it means this is a product you take on purpose during a window, not something that installs itself and stays.
Our formula is one organism at a disclosed count, in a small prebiotic matrix, in a vegetarian capsule. No proprietary blend. No fourteen-strain list where nobody tells you how much of anything is in there.
The difference
What the category does. What we do.
The typical shelf probiotic
Big numbers, small disclosure
- A long strain list with a single combined CFU total, so no individual organism's dose is knowable.
- "Proprietary blend" language that hides the actual ratios.
- Bacterial strains that require refrigeration, or lose viability in a hot mailbox.
- Genus and species on the label with no strain designation at all.
- Research citations borrowed from strains the product does not contain.
- Filler-heavy capsules with excipients that are there for the machine, not for you.
The IOH standard
One organism, named and counted
- A single organism at 10 billion CFU per two-capsule serving. Nothing hidden behind a blend.
- The strain designation printed on our label, so you can ask us about it and we can answer.
- Shelf stable at room temperature. Refrigeration optional, never required.
- Inulin, FOS, and guar gum as a prebiotic matrix, and that is the whole excipient story.
- We tell you which research used which strain and dose, including where ours differs.
- Vegetarian hypromellose capsule. No dairy fillers, no artificial colors.
What it supports
Four reasons this sits in my own cabinet
01
It survives the trip
Acid tolerance and heat tolerance are built into the organism rather than bolted on with a coating. It arrives in the intestinal tract intact and works as it passes through.
02
Antibacterial antibiotics do not target it
A yeast is not what an antibacterial drug is designed to act on. That is the single most practical reason people reach for this organism specifically rather than a bacterial probiotic.
03
Supports a healthy gut flora balance
It supports a balanced intestinal environment and a balanced intestinal response to ordinary internal and environmental stressors — travel, unfamiliar food, hard training blocks, high-stress stretches.
04
The prebiotic matrix is doing work
Inulin, fructooligosaccharides, and guar gum are not there as filler. They are fermentable fibers that feed the beneficial bacteria you already have while the yeast is passing through.
The signature section
Three gates every probiotic has to pass
Most probiotic marketing talks about the CFU count on the bottle. The count on the bottle is the starting number, not the arriving number. Here is what actually stands between a capsule and the part of you it is meant to reach.
Gate 01 — Acid
The stomach
Gastric pH is aggressive by design. Many bacterial strains need an enteric shell or a delayed-release capsule to get past it, and every added layer is another manufacturing variable that can fail.
Why a yeast clears it: acid tolerance is characteristic of this organism itself, not a property of the capsule around it.
Gate 02 — Bile
The small intestine
Bile salts are detergents. They are extremely effective at disrupting cell membranes, which is exactly what they are supposed to do to fats — and incidentally to fragile organisms.
Why a yeast clears it: the yeast cell wall is a fundamentally different structure than a bacterial cell wall, and it is more robust against this exposure.
Gate 03 — Antibiotics
The medication problem
This is the gate that stops nearly every bacterial probiotic. If you are taking an antibacterial drug, you are taking something specifically designed to act on bacteria — including the ones in the capsule you just swallowed.
Why a yeast clears it: antibacterial antibiotics do not act on yeast. This is the whole reason to choose this organism over a Lactobacillus blend during that window.
Straight talk
Antifungal medication is the exception, and it is a real one. An antifungal drug is designed to act on yeast, and this product is a yeast. If you are taking one, this is not the probiotic for that window. There is a full FAQ on that below and I would rather you read it than skip it.
Inside the formula
Every ingredient, every dose, no blend hiding
Saccharomyces boulardii
10 Billion CFU
Saccharomyces cerevisiae var. boulardi MBPL-SBM6 — per 2-capsule serving
A non-pathogenic probiotic yeast, first isolated in the 1920s from tropical fruit peels. Genomically it sits within the Saccharomyces cerevisiae family, which is why the label carries the full varietal name, but it behaves differently from baker's or brewer's yeast and it is unrelated to the Candida species people usually have in mind when they hear the word yeast.
It supports the health of the intestinal tract, helps encourage a healthy gut flora balance, and supports a balanced intestinal response to normal internal and environmental stressors. It reaches steady levels in the colon within about three days of consistent use and is cleared within a few days of stopping.
Straight talk on the strain
Most of the widely cited human research on S. boulardii was run on the CNCM I-745 strain. Our label declares MBPL-SBM6. Probiotic effects are strain specific — that is not a marketing nuance, it is the actual state of the science — so we are not going to hand you a trial result from a different strain and let you assume it belongs to this bottle. What we will tell you is that 10 billion CFU per serving sits in the same general range used across the published S. boulardii literature, and that the species-level properties described on this page — acid tolerance, transient occupancy, indifference to antibacterial drugs — are properties of the organism itself.
Inulin and Fructooligosaccharides (FOS)
Prebiotic matrix
Amount not individually declared on the Supplement Facts panel
Fermentable fibers that serve as substrate for the beneficial bacteria already resident in your colon. Where the yeast is a visitor, these feed the residents. Including them is a deliberate choice — a probiotic capsule that supports only the organism it delivers is doing half the job.
Straight talk
These appear in Other Ingredients, not in the Supplement Facts panel, which means the amount is not disclosed and is small — a matrix, not a therapeutic fiber dose. If you want a meaningful prebiotic fiber intake, that comes from food or from a dedicated fiber product, not from this capsule. Also worth knowing: some people with significant fermentation sensitivity react to inulin and FOS even in small amounts. If that is you, start with one capsule.
Guar Gum
Matrix
Soluble fiber, flow and stability agent
A soluble fiber from the guar bean. In a capsule this size its practical job is powder flow and stability, and it contributes modestly to the prebiotic character of the matrix.
Vegetarian Capsule
Hypromellose
Hypromellose and purified water — no gelatin
Plant-derived hypromellose. No gelatin, no bovine or porcine source, no titanium dioxide, no artificial colorants. Suitable for vegetarian and vegan use.
Supplement Facts
| Amount per Serving | % Daily Value |
|---|---|
| Saccharomyces boulardii 10 Billion CFU (Saccharomyces cerevisiae var. boulardi MBPL-SBM6) | * |
* Daily Value (DV) not established
Other Ingredients: Vegetarian Capsule (Hypromellose, Purified Water), Inulin, Fructooligosaccharides, Guar Gum.
Transcribed from the printed label. The label panel is also shown in the product images.
The short version
Four questions, answered plainly
What it is
A single-organism probiotic yeast supplement. 10 billion CFU of Saccharomyces boulardii per two-capsule serving, in a small prebiotic matrix of inulin, FOS, and guar gum.
60 vegetarian capsules. 30 servings. Shelf stable.
What it does
Supports the health of the intestinal tract. Helps encourage a healthy gut flora balance. Supports a balanced intestinal response to normal internal and environmental stressors.
Supports normal gastrointestinal function during temporary disruptions to the normal balance of gut flora.
Who it's for
- Anyone who wants gut flora support that is not affected by antibacterial medication
- Frequent travelers and people eating unfamiliar food
- Athletes in heavy training or racing blocks
- People who react poorly to multi-strain bacterial blends and want one organism at a known dose
How to take it
2 capsules daily, ideally between meals, or as directed by your physician. Some practitioners use 1 to 2 capsules one to two times daily depending on the situation.
Room temperature storage is fine. Refrigeration is optional and only helps preserve freshness. Do not open the capsule into a hot liquid — heat can reduce viability.
Honest expectations
How to evaluate this over 90 days
I am not going to tell you what day something happens. Nobody honest can. What I can give you is a structured way to judge whether this belongs in your regimen, so you are making a decision on evidence rather than on hope.
Days 1–14
Tolerance and consistency
The only question in this window is whether it sits well with you. Two capsules daily, between meals, every day. If inulin and FOS are an issue for your system you will know quickly — drop to one capsule and hold there. Note anything you notice, good or otherwise, in writing rather than from memory.
Days 15–45
Situational testing
This is where the product earns or loses its place. Use it through the situations you bought it for — the travel week, the training block, the stretch of restaurant food, the antibiotic course your physician has you on. Compare against how those same situations have historically gone for you.
Days 46–90
Decide what role it plays
Two honest options, and both are fine. Daily maintenance, or a targeted tool you keep on the shelf for specific windows. Because this organism is transient and clears within days of stopping, situational use is a legitimate strategy, not a compromise. Talk to your physician about which fits you.
What to look for
Read any probiotic label against these rows
Take this with you the next time you are standing in front of a shelf. It works on our bottle and it works on everyone else's.
| What to check | Typical off-the-shelf probiotic | IOH Saccharomyces Boulardii |
|---|---|---|
| Dose transparency | One combined CFU total across many strains, so no single organism's dose is knowable | One organism, 10 billion CFU, stated on the panel |
| Proprietary blend | Common, and it exists to keep ratios private | None. There is nothing to hide behind |
| Strain identification | Often genus and species only, with no strain designation | Full varietal and strain designation printed on the label |
| Antibiotic compatibility | Bacterial strains are targets of antibacterial drugs | A yeast — antibacterial antibiotics do not act on it |
| Storage requirement | Many bacterial products need refrigeration or lose viability in transit | Shelf stable at room temperature. Refrigeration optional |
| Prebiotic support | Frequently absent, or present only as a marketing mention | Inulin, FOS, and guar gum included in the matrix |
| Capsule composition | Gelatin, dairy carriers, titanium dioxide, artificial colorants | Vegetarian hypromellose. No gelatin, no dyes, no dairy filler |
| Honesty about limits | Research from other strains presented as if it applies | We name the strain-specific research gap on this page, in writing |
Proof, not promises
What we will put in writing
- One organism at a disclosed count. 10 billion CFU per two-capsule serving, printed on the panel, not buried in a blend.
- The strain designation is on the label. If you email us and ask about it, you will get an answer instead of a deflection.
- Four other ingredients. Capsule, inulin, FOS, guar gum. That is the entire excipient list.
- Vegetarian, no gelatin, no dairy carrier, no artificial colors.
- Shelf stable, so what you buy is not depending on a cold chain nobody controlled.
- We tell you on this page that the most-cited research used a different strain designation. Nobody makes you disclose that. We do it anyway.
- We tell you it does not permanently colonize, because that is true and it changes how you should use it.
- We tell you antifungal medication is a real conflict rather than leaving it in fine print.
Product image
and printed label panel
shown in the images above
Manufacturing and standardization
What we can document for this product
A note on how we write this section. Every IOH product page carries only the quality claims documented for that specific product. We do not move a certificate of analysis, a certification mark, or a testing claim from one bottle to another because it reads well. What follows is what we can stand behind for this formula.
Single-organism formulation
One declared organism at one declared count. No blend, no proprietary matrix, no combined CFU figure covering multiple strains.
Strain designation disclosed
The full varietal and strain identifier appears on the printed Supplement Facts panel, not just the species name.
Minimal excipient load
Four other ingredients, all of which serve either a prebiotic or a flow-and-stability purpose. No colorants, no dairy carriers, no unnecessary fillers.
Room-temperature stable
Stable at room temperature. Refrigeration is optional and serves only to preserve freshness. Keep it away from heat and direct sun.
There is no lot-specific certificate of analysis published in the images for this product at this time. When we have one to show you, it will appear here and in the product images, and we will say which lot it covers.
Ironman finish. Not a product claim.
"I have spent 33 years watching people take a fourteen-strain probiotic and hope. I would rather hand you one organism, tell you exactly how much of it is in the capsule, tell you what it does and does not do, and let you decide. This is what I reach for when my own gut is under load — travel, a race block, a course of medication my physician put me on. It is not the answer to everything. It is a specific tool for a specific job, and it is honest about which job that is."
Dr. Andreas Boettcher, B.S., D.C., C.F.M.P.
Founder, It's Only Halftime
Ironman Triathlete/Master's Men's Physique Competitor/Medication-Free at 56/33 Years of Clinical Practice
Stacks
What we pair this with, and why
A stack only earns its place if there is a reason the pairing works. Here is the mechanism behind each one.
Stack 01
With Probiotic 40
A yeast and a bacterial consortium are not redundant, they are two different kinds of organism doing two different jobs. Probiotic 40 supplies nine Lactobacillus and Bifidobacterium strains, which are the kind of organisms that populate a healthy gut. S. boulardii is a transient yeast that works as it passes through and is not a target of antibacterial drugs.
Which means the pairing has a built-in sequence. Through a course of antibacterial medication, the yeast is the one still working. Once that course is finished, the bacterial strains are what help repopulate. Run both and you have the window covered from both directions.
Stack 02
With Detox Binder
Timing is the entire mechanism here, and getting it wrong wastes both products. A binder works by being deliberately non-selective — that is the point of it — which means it will also bind whatever else is in the gut lumen at the same time, including a probiotic organism.
Separate them by at least two hours. Binder on its own schedule, S. boulardii on its own between meals. Taken together in the same window you are largely feeding the binder.
Stack 03
With Gut RestoreX
Barrier support and flora support address two different layers of the same system. Gut RestoreX is aimed at the intestinal lining and the microbiome environment; S. boulardii supports the flora balance living against that lining.
Structure and population. Asking one product to carry both jobs is how formulas end up underdosed in two directions instead of adequate in one. This is the pairing I reach for through a heavy travel and racing stretch.
Ask your physician before combining supplements, particularly if you take prescription medication. Each product above has its own label, its own directions, and its own warnings — read them rather than assuming the stack inherits anything from this page.
I built the page this way because I would want to read it before I swallowed something. One organism, the real count, the real limits, and the one medication conflict that actually matters. If that costs us a sale to somebody who wanted a bigger number on the bottle, so be it.
Stay Strong,
Dr. Andreas
Dr. Andreas Boettcher, B.S., D.C., C.F.M.P.
FAQ
Questions, answered.
Can I take this while I am on an antibiotic?
This is the most common reason people choose this organism, and the reasoning is mechanical rather than promotional. Antibacterial antibiotics are designed to act on bacterial cell machinery. Saccharomyces boulardii is a yeast, so it is not what those drugs are built to target — which is why it is not meaningfully affected by them the way a Lactobacillus or Bifidobacterium product would be.
That said, this is a conversation to have with the physician who prescribed the antibiotic, not a decision to make off a product page. Tell them exactly what you are taking and let them advise on timing and duration.
Are there medications I should not take this with?
Yes, and this one matters enough that I want it stated plainly rather than in fine print.
- Antifungal medications. This includes drug classes such as the azoles (for example fluconazole, itraconazole, ketoconazole), the polyenes (for example nystatin, amphotericin B), and the echinocandins. These drugs are designed to act on yeast. This product is a yeast. Taking them together works against both.
- Immunosuppressive therapy. Discuss any live-organism supplement with your physician if you are on immunosuppressants, chemotherapy, or high-dose corticosteroids.
Beyond those, tell your physician about every supplement you take, including this one. That is true regardless of what any label says.
Is there anyone who should not take this at all?
Yes. Do not take this product, and speak with your physician first, if any of the following apply to you:
- You are immunocompromised, immunosuppressed, or critically ill
- You have a central venous catheter or an indwelling line of any kind
- You have a known yeast allergy or sensitivity
- You are pregnant or nursing
- You are taking an antifungal medication
- The product is for a child, unless a pediatrician has advised it
Live-organism supplements are not appropriate for everyone, and the population above is exactly where caution is warranted. If you are not sure which category you fall into, ask your physician rather than guessing.
Is this the same as the yeast that causes problems? Will it make a yeast issue worse?
Saccharomyces boulardii is not Candida. They are different organisms and they are not closely related. It is also not the same as baker's or brewer's yeast in behavior, even though genomic work places it within the broader Saccharomyces cerevisiae family, which is why our label carries the full varietal name.
If you have an active yeast-related condition under a physician's care, that is a conversation to have with them before adding any live-yeast supplement. I am not going to make a claim in either direction on a product page about a condition you are being treated for.
How much should I take, and when?
Two capsules daily, ideally between meals. That is one serving and gives you 10 billion CFU. In clinical practice some practitioners use 1 to 2 capsules one to two times daily depending on the situation — follow your own physician's direction over anything on this page.
At two capsules daily, a 60-capsule bottle is 30 servings and a 30-day supply. If your physician has you at a higher intake, the bottle will last proportionally less time.
Does it need to be refrigerated?
No. It is stable at room temperature, which is one of the practical advantages of a yeast over most bacterial probiotics. You can refrigerate it to help preserve freshness if you like, but it is optional.
Two things to avoid: heat and direct sunlight. And if you open a capsule to mix the contents into food or a drink, do not use anything hot — heat can reduce viability.
Does it permanently colonize my gut?
No, and I want to be direct about that because a lot of probiotic marketing implies otherwise. S. boulardii is not a native resident of the human gut. It reaches steady levels in the colon within roughly three days of consistent use, works while it is passing through, and is cleared within a few days after you stop taking it.
Practically, that means two things. It works while you are taking it, so consistency matters. And using it situationally — through a travel stretch, a training block, a medication window — is a perfectly legitimate strategy rather than a half measure.
Can I take it alongside a bacterial probiotic?
They are different organisms doing different things, and there is no mechanical conflict between them. Whether you need both is a different question and depends on what you are actually trying to support. Ask your physician rather than stacking on assumption — more organisms is not automatically better.
Why one organism instead of a fourteen-strain blend?
Because with one organism you can know the dose. In a fourteen-strain product with a single combined CFU total, you cannot tell whether a given strain is present at a meaningful amount or at a token amount included so it can appear on the label. We would rather give you one organism, name it, count it, and let you evaluate that than give you a longer list you cannot audit.
Is the inulin and FOS going to bother my stomach?
For most people the amounts here are small enough to be a non-issue — they are a matrix, not a fiber dose. But some people are genuinely sensitive to fermentable fibers, and if you are one of them you will know within the first few days. Start with one capsule and see how it sits before moving to two.
The close
One organism. The real number. The real limits.
You can buy a probiotic with fourteen strains and a bigger number on the front and no way to audit any of it. That product exists on every shelf in the country and it will always look more impressive than this one.
What you cannot easily buy is a page that tells you which strain the research was run on, admits the label says something different, explains that the organism does not stay, and names the medication that conflicts with it — before you spend a dollar.
That is not modesty. It is the only version of this business I am willing to run. If you want a probiotic you can actually reason about, this is it.
Trademark attributions: no branded or trademarked ingredients are used in this formula. All ingredients are declared by common or usual name on the Supplement Facts panel.
Manufactured for IOH Nutrition LLC. Storage: keep tightly closed in a cool, dry place away from heat and direct sunlight. Refrigeration is optional. Keep out of reach of children. Do not use if the safety seal is broken.
Consult your physician before use, particularly if you are pregnant or nursing, immunocompromised, have an indwelling catheter, have a known yeast sensitivity, are taking antifungal or immunosuppressive medication, or have any diagnosed medical condition. This product is not intended for children unless directed by a pediatrician.
These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease.
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