Drug & supplement interaction

Saccharomyces Boulardii + Cefazolin

Cefazolin brand name: Ancef.

No Known Interaction

Medically reviewed by Dr. Brian Staiger, PharmD, BCPS · Updated July 2026 · Pair last verified Sep 13, 2026

The bottom line No known interaction

We found no known interaction between Saccharomyces Boulardii and Cefazolin in our sources. Absence of a documented interaction is not the same as proven safety, and does not guarantee one does not exist. Do not start, stop, or change a medication or supplement based on this page; confirm with your pharmacist or doctor first. Additionally, although there is no interaction, the two are separately associated with some of the same side effects, which would make a new symptom harder to attribute to one or the other.

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Interaction report

Saccharomyces Boulardii and Cefazolin

We checked these two against our interaction database. Here is what we found.

No Known Interaction Found

We did not find a documented interaction between Cefazolin and Saccharomyces Boulardii in our sources. This does not guarantee that the combination is completely free of risk — there is often limited research on supplements and herbal products, especially around drug interactions.

If you decide to take both, the practical routine is simple: add one new thing at a time and note the date you started it. If the combination is going to disagree with you, it usually shows in the first days to a couple of weeks — and a start date turns “I’ve been feeling off” into something a pharmacist can actually work with. Do not stop a prescribed medicine on your own.

Always talk with your pharmacist or doctor before making changes to your medications or supplements, particularly if you take several medications or have an ongoing health condition.

Saccharomyces Boulardii safety at a glance

Saccharomyces Boul... overall Use caution Generally safe for healthy adults but should be avoided by people who are critically ill or immunocompromised.

Pregnancy Use caution Not enough reliable safety data; speak with your doctor before use.

Breastfeeding Use caution Limited safety information is available, so use only with medical advice.

Safety guidance is general; always confirm with your pharmacist or doctor for your situation.

Still wondering about combining Cefazolin and Saccharomyces Boulardii? Ask Dr. Brian Staiger, PharmD, BCPS directly ›

How we checked

Why No Interaction Is Listed for Cefazolin

Interactions in our licensed database are recorded against drug classes, not just single drug names. Cefazolin is filed under 5 classifications — including organic anion transporter 3 (oat3) substrates, organic anion transporter 1 (oat1) substrates, antibiotic drugs. Saccharomyces Boulardii has documented interactions with 1 drug class — the most serious being antifungals (minor) — and none of Cefazolin’s classifications are among them.

Classification data comes from our licensed Natural Medicines dataset. A medication can belong to classes beyond those recorded there, so this describes how the check was run — it is not a safety guarantee.

Keep it in perspective

Saccharomyces Boulardii Does Interact With Other Medications

Saccharomyces Boulardii has 40 minor known drug interactions in our database — Cefazolin isn’t one of them. If you take anything else, check it against the full list below.

Minor 40 No known interaction 2,790 (incl. Cefazolin)

Taking anything else?

Check Another of Your Medications Against Saccharomyces Boulardii

Covers the 2,830 medications we’ve checked against Saccharomyces Boulardii. Pick one to open its full report.

What to actually watch for

No Interaction Found — But Data Suggests Saccharomyces Boulardii and Cefazolin May Share Several of the Same Side Effects

This is not an interaction. Neither one changes how your body handles the other, and nothing here says they react together. What our sources do show is that each has separately been linked to the effects below — so taking both can make those effects more likely to turn up, and harder to pin on one or the other if they do.

Reduced appetite / Stomach pain / Vomiting / Nausea Additional detail
Saccharomyces Boulardii
“Rarely, oral use of Saccharomyces boulardii has caused gastrointestinal complaints, such as abdominal cramps, flatulence, nausea, vomiting, and decreased appetite.”

Saccharomyces Boulardii · Natural Medicines adverse-effect record, reported in flatulence.
2 sources cited

98731. Flatley EA, Wilde AM, Nailor MD. Saccharomyces boulardii for the prevention of hospital onset Clostridium difficile infection. J Gastrointestin Liver Dis. 2015;24(1):21-4. PubMed

107608. Awoyemi A, Mayerhofer C, Felix AS, et al. Rifaximin or Saccharomyces boulardii in heart failure with reduced ejection fraction: Results from the randomized GutHeart trial. EBioMedicine 2021;70:103511. PubMed
Cefazolin

Listed in the ADVERSE REACTIONS section of the FDA label for Cefazolin. Read the label on DailyMed ›
Diarrhea Additional detail
Saccharomyces Boulardii
“Rarely, oral use of Saccharomyces boulardii has been associated with fungemia in both immunocompromised and immunocompetent patients. Numerous cases of Saccharomyces fungemia have been reported in critically ill intensive care unit (ICU) patients, particularly those with indwelling or central venous catheters, those receiving enteral feeding, or those receiving broad-spectrum antibiotics.”

Saccharomyces Boulardii · Natural Medicines adverse-effect record, reported in crohn disease.
6 sources cited

1247. Niault M, Thomas F, Prost J, et al. Fungemia due to Saccharomyces species in a patient treated with enteral Saccharomyces boulardii. Clin Infect Dis 1999;28:930.

4357. Pletinex M, Legein J, Vandenplas Y. Fungemia with Saccharomyces boulardii in a 1-year-old girl with protracted diarrhea. J Pediatr Gastroenterol Nutr 1995;21:113-5. DOI

4358. Fredenucci I, Chomarat M, Boucaud C, et al. Saccharomyces boulardii fungemia in a patient receiving ultra-levure therapy. Clin Infect Dis 1998;27:222-3.

4360. Elmer GW, McFarland LV, Surawicz CM, et al. Behaviour of Saccharomyces boulardii in recurrent Clostridium difficile disease patients. Aliment Pharmacol Ther 1999;13:1663-8.

7329. Cesaro S, Chinello P, Rossi L, Zanesco L. Saccharomyces cerevisiae fungemia in a neutropenic patient treated with Saccharomyces boulardii. Support Care Cancer 2000;8:504-5. PubMed

14459. Munoz P, Bouza E, Cuenca-Estrella M, et al. Saccharomyces cerevisiae fungemia: an emerging infectious disease. Clin Infect Dis 2005;40:1625-34. PubMed
Cefazolin

Listed in the ADVERSE REACTIONS section of the FDA label for Cefazolin. Read the label on DailyMed ›

Reported for Saccharomyces Boulardii but not commonly for Cefazolin: bloating or gas and a higher chance of infection.

Effects for Cefazolin come from the ADVERSE REACTIONS section of its FDA label; effects for Saccharomyces Boulardii come from the Natural Medicines adverse-effect record, quoted above. Where a percentage is shown, it is the share of 11,986 voluntary FDA FAERS reports for Cefazolin that mention that effect — a reporting proportion, not an incidence rate and not evidence the drug caused it. Wording is matched across sources by our own clinical vocabulary, so treat this as a prompt to pay attention, not a diagnosis.

Overlapping uses

What Cefazolin Is Prescribed For, and What Saccharomyces Boulardii Has Been Studied For

These two come up together because they touch the same health topic — not because they do the same job. Cefazolin is a prescription medicine with approved uses on its FDA label. Saccharomyces Boulardii is a supplement: what follows is what researchers have looked at it for, and how strong that evidence is.

Cefazolin is prescribed for: Cefazolin Injection is used to treat bacterial infections in adults and children 1 month of age and older, including respiratory tract infections, urinary tract infections, skin and skin structure infections, biliary tract infections, bone and joint infections, genital infections (such as prostatitis and epididymitis), septicemia (a serious bloodstream infection), and endocarditis (infection of the heart's inner lining). It is also used in adult patients — and in pediatric patients aged 10 to 17 years for the premixed formulation — to help prevent infection around the time of surgery, particularly for procedures that carry a higher risk of postoperative infection.

Saccharomyces Boulardii has been studied for:

Postoperative infection studied, not established Saccharomyces Boulardii has been studied for this. Natural Medicines rates the evidence: Insufficient Reliable Evidence To Rate Read what the research shows

Saccharomyces Boulardii for postoperative infection

It is unclear if oral Saccharomyces boulardii prevents postoperative infection.

Effectiveness ratings and the research summaries above are the verbatim record from the Natural Medicines database, which grades evidence from “Effective” down to “Insufficient Reliable Evidence To Rate”. A rating below the top of that scale means researchers have looked at it — not that it works, and never that it can stand in for a prescribed medicine. Do not stop or replace Cefazolin on your own; if you are taking Saccharomyces Boulardii for the same health topic, tell your prescriber, especially if the medicine is being adjusted to a target.

Everything else you take

See Every Supplement That Interacts With Cefazolin

This page covers Saccharomyces Boulardii only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Cefazolin page lists 43 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Asarabacca (major), Siberian Cocklebur (major), African Wild Potato (moderate), Aristolochia (moderate) and Bacillus Coagulans (moderate).

By severity: 2 major · 39 moderate · 2 minor.

From our pharmacist’s overview on the Cefazolin page

“Cefazolin (Ancef), an antibiotic given by injection, usually before surgery or for skin and bloodstream infections, carries 43 supplement interactions on file, and the two rated major are where I would start reading. Siberian cocklebur and asarabacca can each damage the kidneys, the same organ that clears cefazolin, and asarabacca is f…”

Reviewed by 2 · Jul 18, 2026

Open the Cefazolin interaction page

One more smart check

Taking Saccharomyces Boulardii as Part of a Dietary Supplement Product? Check It for Interactions

We hold 608 real supplement products containing Saccharomyces Boulardii, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Saccharomyces Boulardii. Even though Saccharomyces Boulardii itself has no known interaction with Cefazolin, another ingredient on your label might. Find your product and we’ll check every ingredient on its label:

How much people look this up

Where Saccharomyces Boulardii and Cefazolin Sit Against Everything Else

Out of every supplement and medication people look up on HelloPharmacist, here is where these two land this week — and which way each has been moving.

Supplement Saccharomyces Boulardii

Top 25%

#258 of 1,452 supplements looked up here in the last 7 days

29 days ago today

Medication Cefazolin

Steady interest

#1,821 of 2,830 medications looked up here in the last 7 days

29 days ago today

Position among everything looked up on this site, not a measure of how commonly either one is used or how important it is. A supplement can climb this list because of a news story. It counts every request to the page, automated ones included, and nothing here identifies anyone.

Where does our data come from?

Source: the Natural Medicines (TRC Healthcare) clinical database — the evidence-graded professional reference for herb & supplement interactions.
Citation library: 103,510 references behind our interaction content, 65,311 of them resolved to verified PubMed/DOI sources. See every Saccharomyces Boulardii reference on this page ↓
Freshness: we automatically re-check this combination every week — this pair was last verified September 13, 2026. The Saccharomyces Boulardii and Cefazolin records this page draws on were last updated July 10, 2026.
What “no known interaction” means: no documented interaction in the sources above — not a guarantee of safety. Supplements are studied far less than prescription drugs, so we say exactly what the evidence supports, and nothing more.

Data structure & sourcing designed and verified by Dr. Brian Staiger, PharmD, BCPS.

Supplement

About Saccharomyces Boulardii

What is Saccharomyces Boulardii?

Acute diarrhea
Antibiotic-associated diarrhea
Traveler's diarrhea
Preventing C. difficile recurrence
General gut health

Saccharomyces boulardii is a beneficial yeast used as a probiotic, with the strongest evidence for preventing and treating certain types of diarrhea, including antibiotic-associated diarrhea. It is generally well tolerated in healthy people, but those who are seriously ill or have weakened immune systems should avoid it because of rare but serious bloodstream infections. Talk with your pharmacist or doctor before starting it.

Saccharomyces cerevisiae var. boulardii · Saccharomycetaceae · Whole yeast cells (probiotic microorganism) · Capsules, tablets, powders (often sold as lyophilized/freeze-dried yeast)

An interaction check asks whether these two react with each other — it does not ask whether Saccharomyces Boulardii is a good idea for someone in your situation. Here is what our Saccharomyces Boulardii record says about it on its own.

Saccharomyces Boulardii: dosing

There is no single official standardized dose for S. boulardii. Products are often measured in milligrams of freeze-dried yeast or in colony-forming units (CFU), and amounts vary widely between brands.The best approach is to follow the directions on the product label and to choose a reputable brand.

From our Saccharomyces Boulardii monograph — the full record covers uses, side effects and every documented interaction.

Read the full Saccharomyces Boulardii monograph & all interactions

Medication

About Cefazolin Injection

What Is Cefazolin Injection Used For?

Brand name: Ancef

Cefazolin Injection is used to treat bacterial infections in adults and children 1 month of age and older, including respiratory tract infections, urinary tract infections, skin and skin structure infections, biliary tract infections, bone and joint infections, genital infections (such as prostatitis and epididymitis), septicemia (a serious bloodstream infection), and endocarditis (infection of the heart's inner lining).

It is also used in adult patients — and in pediatric patients aged 10 to 17 years for the premixed formulation — to help prevent infection around the time of surgery, particularly for procedures that carry a higher risk of postoperative infection.

Most-Reported Side Effects for Cefazolin

From FAERS, the FDA’s public side-effect reporting system (11,986 reports, all brands). Reports are voluntary and are not proof the drug caused the effect.

Hypotension 702 reports

Anaphylactic reaction 644 reports

Anaphylactic shock 601 reports

Rash 592 reports

Fever 512 reports

See full Cefazolin Injection drug information

Keep checking

Other Drugs & Saccharomyces Boulardii

Browse every other medication we’ve checked against Saccharomyces Boulardii — both the ones with a known interaction and the ones without. Select any drug for the full detail.

0Major

0Moderate

40Minor

2,789No known interaction

40 Minor 2,789 No interaction

Minor

40 interactions

No interaction 2,789 drugs checked — show the list

We also checked Saccharomyces Boulardii against these medications and found no known interaction in our sources. Open any page to confirm.

Showing the 60 most looked-up of 2,789 medications checked with no known interaction — see the full Saccharomyces Boulardii list.

See the full Saccharomyces Boulardii interactions page

See every supplement checked against Cefazolin, ranked by severity

Evidence & sources

Saccharomyces Boulardii References

The 26 references that drive our Saccharomyces Boulardii monograph and interaction data, from the evidence-graded Natural Medicines (TRC Healthcare) database. Citations with a link open the study on PubMed or the publisher’s site.

Niault M, Thomas F, Prost J, et al. Fungemia due to Saccharomyces species in a patient treated with enteral Saccharomyces boulardii. Clin Infect Dis 1999;28:930.
Pletinex M, Legein J, Vandenplas Y. Fungemia with Saccharomyces boulardii in a 1-year-old girl with protracted diarrhea. J Pediatr Gastroenterol Nutr 1995;21:113-5. DOI
Fredenucci I, Chomarat M, Boucaud C, et al. Saccharomyces boulardii fungemia in a patient receiving ultra-levure therapy. Clin Infect Dis 1998;27:222-3.
Elmer GW, McFarland LV, Surawicz CM, et al. Behaviour of Saccharomyces boulardii in recurrent Clostridium difficile disease patients. Aliment Pharmacol Ther 1999;13:1663-8.
Lewis SJ, Freedman AR. Review article: the use of biotherapeutic agents in the prevention and treatment of gastrointestinal disease. Aliment Pharmacol Ther 1998;12:807-22. PubMed
Cesaro S, Chinello P, Rossi L, Zanesco L. Saccharomyces cerevisiae fungemia in a neutropenic patient treated with Saccharomyces boulardii. Support Care Cancer 2000;8:504-5. PubMed
Hennequin C, Thierry A, Richard GF, et al. Microsatellite typing as a new tool for identification of Saccharomyces cerevisiae strains. J Clin Microbiol 2001;39:551-9.
Plein K, Hotz J. Therapeutic effects of Saccharomyces boulardii on mild residual symptoms in a stable phase of Crohn's disease with special respect to chronic diarrhea - a pilot study. Z Gastroenterol 1993;31:129-34.
Borriello SP, Hammes WP, Holzapfel W, et al. Safety of probiotics that contain lactobacilli or bifidobacteria. Clin Infect Dis 2003;36:775-80. PubMed
Marteau P, Seksik P. Tolerance of probiotics and prebiotics. J Clin Gastroenterol 2004;38:S67-9. PubMed
Munoz P, Bouza E, Cuenca-Estrella M, et al. Saccharomyces cerevisiae fungemia: an emerging infectious disease. Clin Infect Dis 2005;40:1625-34. PubMed
Lherm, T., Monet, C., Nougiere, B., Soulier, M., Larbi, D., Le Gall, C., Caen, D., and Malbrunot, C. Seven cases of fungemia with Saccharomyces boulardii in critically ill patients. Intensive Care Med 2002;28(6):797-801. PubMed
Riquelme, A. J., Calvo, M. A., Guzman, A. M., Depix, M. S., Garcia, P., Perez, C., Arrese, M., and Labarca, J. A. Saccharomyces cerevisiae fungemia after Saccharomyces boulardii treatment in immunocompromised patients. J Clin.Gastroenterol. 2003;36(1):41- PubMed
Cherifi, S., Robberecht, J., and Miendje, Y. Saccharomyces cerevisiae fungemia in an elderly patient with Clostridium difficile colitis. Acta Clin Belg. 2004;59(4):223-224. PubMed
Ellouze O, Berthoud V, Mervant M, Parthiot JP, Girard C. Septic shock due to Sacccaromyces boulardii. Med Mal Infect. 2016;46(2):104-105.
Appel-da-Silva MC, Narvaez GA, Perez LRR, Drehmer L, Lewgoy J. Saccharomyces cerevisiae var. boulardii fungemia following probiotic treatment. Med Mycol Case Rep. 2017;18:15-7. PubMed
Atici S, Soysal A, Karadeniz Cerit K, et al. Catheter-related Saccharomyces cerevisiae Fungemia Following Saccharomyces boulardii Probiotic Treatment: In a child in intensive care unit and review of the literature. Med Mycol Case Rep. 2017;15:33-35. PubMed
Martin IW, Tonner R, Trivedi J, et al. Saccharomyces boulardii probiotic-associated fungemia: questioning the safety of this preventive probiotic's use. Diagn Microbiol Infect Dis. 2017;87(3):286-8. PubMed
Romanio MR, Coraine LA, Maielo VP, Abramczyc ML, Souza RL, Oliveira NF. Saccharomyces cerevisiae fungemia in a pediatric patient after treatment with probiotics. Rev Paul Pediatr 2017;35(3):361-4.
Roy U, Jessani LG, Rudramurthy SM, et al. Seven cases of Saccharomyces fungaemia related to use of probiotics. Mycoses 2017;60(6):375-380.
Romanio MR, Coraine LA, Maielo VP, Abramczyc ML, Souza RL, Oliveira NF. Saccharomyces cerevisiae fungemia in a pediatric patient after treatment with probiotics. Rev Paul Pediatr. 2017 Jul-Sep;35(3):361-364. doi: 10.1590/1984-0462/;2017;35;3;00014.
Flatley EA, Wilde AM, Nailor MD. Saccharomyces boulardii for the prevention of hospital onset Clostridium difficile infection. J Gastrointestin Liver Dis. 2015;24(1):21-4. PubMed
Ventoulis I, Sarmourli T, Amoiridou P, et al. Bloodstream infection by Saccharomyces cerevisiae in two COVID-19 patients after receiving supplementation of Saccharomyces in the ICU. J Fungi (Basel). 2020;6(3):98. PubMed
Wombwell E, Bransteitter B, Gillen LR. Incidence of Saccharomyces cerevisiae fungemia in hospitalised patients administered Saccharomyces boulardii probiotic. Mycoses 2021;64(12):1521-1526.
Rannikko J, Holmberg V, Karppelin M, et al. Fungemia and Other Fungal Infections Associated with Use of Saccharomyces boulardii Probiotic Supplements. Emerg Infect Dis 2021;27(8):2090-6.
Awoyemi A, Mayerhofer C, Felix AS, et al. Rifaximin or Saccharomyces boulardii in heart failure with reduced ejection fraction: Results from the randomized GutHeart trial. EBioMedicine 2021;70:103511. PubMed

Medication overviews come from MedlinePlus (NIH); supplement label data from the NIH Dietary Supplement Label Database. Content is written and reviewed by licensed HelloPharmacist pharmacists — see our data sources and editorial standards.

Related: nutrient depletion

Cefazolin Is Linked to Lower Levels of 7 Nutrients

Natural Medicines records Cefazolin as a medicine that can lower these. This is not an interaction with Saccharomyces Boulardii — it is a separate effect of the medicine, and it is a reason some people are advised to supplement rather than to avoid one:

Read the full Cefazolin nutrient depletion report ›

Depletion records come from the licensed Natural Medicines database. Do not start a supplement on the strength of this page — ask your pharmacist or doctor whether it applies to you.

Pharmacist Counseling Corner

Taking Saccharomyces Boulardii and Cefazolin Together: Common Questions

Is it safe to take Saccharomyces Boulardii with Cefazolin?

We do not list a known interaction between Saccharomyces Boulardii and Cefazolin. That does not guarantee the combination is risk-free, so confirm with your pharmacist or doctor — especially if you take other medications or have a health condition.

Do Saccharomyces Boulardii and Cefazolin have any of the same side effects?

Yes — our sources link each of them separately to 5 of the same effects. That is not an interaction: neither changes how your body handles the other. It does mean that if one of those effects turns up, it can be harder to tell which one is behind it. They are listed on this page with the source behind each.

Are Saccharomyces Boulardii and Cefazolin used for the same thing?

They overlap in purpose, which usually means the real question is whether you need both rather than whether they are safe together. This page lists the shared uses and how strong the evidence is for Saccharomyces Boulardii in each. That is a conversation for your prescriber, especially if Cefazolin is being adjusted to a target.

How was the Saccharomyces Boulardii and Cefazolin combination checked?

Interactions in our licensed database are recorded against drug classes. Cefazolin is filed under 5 classifications, and Saccharomyces Boulardii has documented interactions with 1 drug class — none of Cefazolin's classifications are among them. A medication can belong to classes beyond those recorded in our dataset, so this describes how the check was run rather than guaranteeing safety.

Does Saccharomyces Boulardii interact with any other medications?

Yes. Saccharomyces Boulardii has 40 documented drug interactions in our database — Cefazolin is simply not one of them. If you take anything else, it is worth checking each one; they are all listed on this page.

Does Cefazolin interact with any supplements?

Yes. Cefazolin has documented interactions with 43 supplements in our database — Saccharomyces Boulardii is not one of them. The Cefazolin interaction page linked on this page lists every one, ranked by severity.

Written and reviewed by the HelloPharmacist editorial staff. Our editorial policy

Where next

Keep Exploring

Saccharomyces Boulardii monograph Uses, safety profile, and every drug interaction in one place Cefazolin Injection drug information The full plain-English guide to this medication Cefazolin supplement interactions Every supplement checked against Cefazolin, ranked by severity Supplement interaction checker Check any supplement or product against your medications Browse medications A–Z Every drug we’ve checked against herbs & supplements References The 26 citations behind this page Ask a pharmacist Free, personal answer from our licensed team

Still Have a Question About Cefazolin and Saccharomyces Boulardii?

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This information is for education only and is not a substitute for professional medical advice. Always check with your pharmacist or doctor before starting, stopping, or combining supplements and medications.