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Saccharomyces Boulardii supplement
Probiotic Yeast

Saccharomyces Boulardii — Research Profile

Evidence:Strong
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This content is for informational purposes only and does not constitute medical advice. Statements about dietary supplements have not been evaluated by the FDA and are not intended to diagnose, treat, cure, or prevent any disease. Individual results may vary — consult your healthcare provider before starting any supplement. Full disclaimer

S. boulardii is a probiotic yeast that is antibiotic-resistant and clinically proven to prevent antibiotic-associated...

S. boulardii is a probiotic yeast that is antibiotic-resistant and clinically proven to prevent antibiotic-associated diarrhea and reduce C. difficile recurrence. A Cochrane review found NNT of 10 for AAD prevention. Standard dose is 250-500mg (5-10 billion CFU) twice daily.

Bottom line: S. boulardii is the best probiotic to take during antibiotic therapy — it is antibiotic-resistant and prevents C. difficile and AAD.

Evidence:Meta-analysis (2015) · 21 RCTs · n=4,780 · high confidence[#1]. See full reference list below.

Key Facts

What it is
A non-pathogenic probiotic yeast that is naturally resistant to antibacterial antibiotics
Primary benefits
  • Prevents antibiotic-associated diarrhea (AAD)
  • Reduces C. difficile infection recurrence
  • Treats acute infectious diarrhea in children
  • Supports gut barrier during antibiotic therapy
Typical dosage
250-500mg (5-10 billion CFU) twice daily
Evidence level
Strong
Safety profile
Generally Safe

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What the Research Says

Saccharomyces Boulardii is a well-documented probiotic yeast with demonstrated efficacy across various clinical applications. As a yeast, it uniquely resists antibacterial antibiotics, making it an ideal adjunct during antibiotic therapy to prevent antibiotic-associated diarrhea (AAD). A systematic review and meta-analysis by Szajewska et al. (2015) found that S. boulardii significantly reduces the risk of AAD with a number needed to treat (NNT) of 10, highlighting its preventive potential.

In addition to AAD prevention, studies have explored its role in managing acute diarrhea and preventing Clostridioides difficile recurrence. McFarland et al. (2010) conducted a systematic review supporting its efficacy in reducing the duration of pediatric acute diarrhea and lowering the risk of recurrent episodes. Furthermore, S. boulardii has been shown to enhance Helicobacter pylori eradication rates when used as an adjuvant therapy. A meta-analysis by Liu et al. (2023) involving 15 RCTs with 2156 participants found that its supplementation improved eradication success and reduced adverse events in children.

Recent studies have also highlighted its benefits in neonatal care, with Gao et al. (2021) reporting that S. boulardii supplementation significantly reduced the incidence of necrotizing enterocolitis (NEC) and feeding intolerance in pre-term infants. These findings underscore its potential as a preventive measure in vulnerable populations.

Overall, Saccharomyces Boulardii stands out as a versatile probiotic with well-documented benefits across multiple clinical settings, supported by rigorous evidence from systematic reviews and meta-analyses.

Benefits of Saccharomyces Boulardii

  • AAD prevention — a Cochrane review (Szajewska & Kolodziej, 2015, 21 RCTs, n=4,780) found S. boulardii reduced AAD risk by 53% (RR 0.47) with NNT of 10
  • C. difficile prevention — McFarland (2010, meta-analysis, 5 RCTs, n=1,076) showed S. boulardii reduced C. difficile recurrence by 43% when used as adjunctive therapy with antibiotics
  • Acute diarrhea in children — Feizizadeh et al. (2014, meta-analysis, 22 RCTs, n=5,029) found S. boulardii reduced duration of acute diarrhea by approximately 1 day in children
  • Toxin degradation — S. boulardii secretes a 54-kDa serine protease that directly cleaves and inactivates C. difficile toxins A and B (Castagliuolo et al., 1999)
Did you know?

Saccharomyces Boulardii is a well-documented probiotic yeast with demonstrated efficacy across various clinical applications.

Forms of Saccharomyces Boulardii

Saccharomyces Boulardii supplement forms compared by bioavailability and best use
FormBioavailabilityBest For
Lyophilized Capsules (250mg)HighStandard clinical dose — most studied form; each 250mg capsule contains ~5 billion CFU
Sachets/PowderHighPediatric use — can be mixed into food or drinks for children

Dosage Recommendations

General recommendation: 250-500mg (5-10 billion CFU) twice daily

Timing: Can be taken at any time relative to antibiotics (antibiotic-resistant)

Dosage by Condition

AAD prevention
250mg twice daily throughout antibiotic courseStrong
C. difficile recurrence prevention
500mg twice daily for 4 weeksStrong
Acute diarrhea (pediatric)
250mg twice daily for 5-7 daysStrong

Upper limit: 1,000mg (20 billion CFU) per day

Side Effects and Safety

Safety profile: Generally Safe

Potential Side Effects

  • Very well tolerated; mild gas in some individuals
  • Fungemia risk in immunocompromised patients or those with central venous catheters (rare but serious)
  • Should not be opened near central line patients — airborne yeast can colonize catheters

Drug & Supplement Interactions

  • Antifungals (fluconazole, nystatin) — will kill S. boulardii and negate probiotic benefit
  • Antibacterial antibiotics — no interaction (S. boulardii is a yeast and inherently resistant)
  • Immunosuppressants — use with caution; fungemia risk in severely immunocompromised
Check Saccharomyces Boulardii interactions with other supplements →
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Related Conditions

Commonly Taken Together

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Frequently Asked Questions

Can I take S. boulardii at the same time as antibiotics?

Yes — this is its primary advantage. S. boulardii is a yeast, so antibacterial antibiotics do not kill it. You can take it at the same time as your antibiotic without spacing doses apart. However, do not take it with antifungal medications like fluconazole, as these will kill the yeast.

Evidence:Meta-analysis (2015) · 21 RCTs · n=4,780 · high confidence[#1]. See full reference list below.

How long should I take S. boulardii after finishing antibiotics?

Continue taking S. boulardii for at least 1-2 weeks after completing your antibiotic course. For C. difficile prevention, clinical trials used 4 weeks of supplementation. S. boulardii does not permanently colonize the gut — it washes out within 3-5 days of stopping.

Is S. boulardii safe for children?

Yes. S. boulardii has been extensively studied in pediatric populations and is recommended by the WHO as an adjunct for acute diarrhea in children. Standard pediatric dosing is 250mg twice daily. It is not recommended for premature infants or immunocompromised children.

What is the best form of Saccharomyces Boulardii to take?

The best form of saccharomyces boulardii depends on your specific health goals, absorption needs, and tolerance. Chelated and standardized extract forms generally offer higher bioavailability than raw or unstandardized versions. Check the product label for third-party testing to ensure potency and purity.

What are the proven benefits of Saccharomyces Boulardii?

Saccharomyces Boulardii has been studied for multiple health applications with varying levels of clinical evidence. The strongest evidence typically comes from randomized controlled trials and meta-analyses published in peer-reviewed journals. Individual responses can vary based on baseline status, dosage, and duration of use.

How much Saccharomyces Boulardii should I take per day?

Saccharomyces Boulardii dosage depends on the specific form, your health goals, and individual factors such as body weight and baseline nutrient status. Following the dose used in clinical trials is generally the most evidence-based approach. Starting at the lower end of the recommended range and adjusting upward is advisable.

When is the best time to take Saccharomyces Boulardii?

Saccharomyces Boulardii timing depends on whether it is fat-soluble or water-soluble and whether it causes digestive sensitivity. Consistency in timing is more important than the specific hour of the day. Taking supplements at the same time daily helps maintain steady levels.

What are the side effects of Saccharomyces Boulardii?

Saccharomyces Boulardii is generally well tolerated at recommended doses, with gastrointestinal discomfort being the most commonly reported side effect. Side effects are typically mild and dose-dependent, resolving with dose reduction or taking with food. Serious adverse effects are rare at standard supplemental doses.

Does Saccharomyces Boulardii interact with any medications?

Saccharomyces Boulardii may interact with certain prescription medications by affecting absorption, metabolism, or pharmacological effects. Always inform your healthcare provider about all supplements you take, especially before surgery or when starting new medications. Spacing supplements and medications by 2 hours reduces most absorption interactions.

Who should consider taking Saccharomyces Boulardii?

Saccharomyces Boulardii is most appropriate for individuals with confirmed deficiency, suboptimal levels, or specific health conditions supported by clinical evidence. People in higher-risk demographics, including older adults and those with restricted diets, may benefit most. Testing baseline levels before supplementing provides the best guidance.

How long does Saccharomyces Boulardii take to show results?

Saccharomyces Boulardii effects vary by the specific health outcome being targeted, with some benefits appearing within days and others requiring weeks to months of consistent daily use. Correcting a deficiency typically shows improvement within 2-4 weeks. A minimum 8-12 week trial at the recommended dose is advisable before evaluating effectiveness.

Is Saccharomyces Boulardii safe for long-term daily use?

Saccharomyces Boulardii is considered safe for long-term use at recommended doses based on available clinical data. Staying within established upper intake limits minimizes the risk of adverse effects over time. Periodic reassessment with a healthcare provider is recommended, especially if health conditions change.

Can you take too much Saccharomyces Boulardii?

Exceeding the recommended dose of saccharomyces boulardii increases the risk of adverse effects without providing additional benefit. Toxicity risk varies by form and individual factors such as kidney and liver function. Mega-dosing is not supported by clinical evidence and should be avoided.

Can I combine Saccharomyces Boulardii with other supplements?

Saccharomyces Boulardii can generally be combined with complementary supplements, though some combinations may affect absorption or create additive effects. Spacing different supplements by 1-2 hours can reduce absorption competition. Consulting a healthcare professional is advisable when combining multiple supplements targeting the same health pathway.

What should I look for when buying a Saccharomyces Boulardii supplement?

Third-party testing from USP, NSF, or ConsumerLab is the most important quality indicator when purchasing saccharomyces boulardii supplements. Look for products that clearly state the specific form, dose per serving, and any relevant standardization percentages. Avoid proprietary blends that hide individual ingredient amounts.

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References

  1. Meta-analysisSzajewska H, Kolodziej M. (2015). Systematic review with meta-analysis: Saccharomyces boulardii in the prevention of antibiotic-associated diarrhoea. Alimentary Pharmacology & Therapeutics. DOI PubMed
  2. Meta-analysisMcFarland LV. (2010). Systematic review and meta-analysis of Saccharomyces boulardii in adult patients. World Journal of Gastroenterology. DOI PubMed
  3. Li M, Xie Y (2025). Efficacy and safety of Saccharomyces boulardii as an adjuvant therapy for the eradication of Helicobacter pylori: a meta-analysis.. Frontiers in cellular and infection microbiology. DOI PubMed
  4. McFarland LV, Li T (2025). Efficacy and safety of Saccharomyces boulardii CNCM I-745 for the treatment of pediatric acute diarrhea in China: a systematic review and meta-analysis.. Frontiers in cellular and infection microbiology. DOI PubMed
  5. Ma F, Huang H, Tian K, Wang W (2025). Efficacy and Safety of <em>Saccharomyces Boulardii</em> with Standard Quadruple Therapy for Eradication of <em>Helicobacter Pylori </em>in Adults: Meta-Analysis.. Journal of the College of Physicians and Surgeons--Pakistan : JCPSP. DOI PubMed
  6. Jiang YZ, Ma K, Cui C, Li ZY, et al. (2025). Effect of Saccharomyces boulardii supplementation to bismuth quadruple therapy on Helicobacter pylori eradication.. BMC gastroenterology. DOI PubMed
  7. Meta-analysisLiu LH, Han B, Tao J, Zhang K, et al. (2023). The effect of Saccharomyces boulardii supplementation on Helicobacter pylori eradication in children: a systematic review and meta-analysis of Randomized controlled trials.. BMC infectious diseases. DOI PubMed
Show 4 more references
  1. Meta-analysisFu H, Li J, Xu X, Xia C, et al. (2022). Effectiveness and Safety of Saccharomyces Boulardii for the Treatment of Acute Gastroenteritis in the Pediatric Population: A Systematic Review and Meta-Analysis of Randomized Controlled Trials.. Computational and mathematical methods in medicine. DOI PubMed
  2. Meta-analysisSzajewska H, Kołodziej M, Zalewski BM (2020). Systematic review with meta-analysis: Saccharomyces boulardii for treating acute gastroenteritis in children-a 2020 update.. Alimentary pharmacology & therapeutics. DOI PubMed
  3. Zhou BG, Chen LX, Li B, Wan LY, et al. (2019). Saccharomyces boulardii as an adjuvant therapy for Helicobacter pylori eradication: A systematic review and meta-analysis with trial sequential analysis.. Helicobacter. DOI PubMed
  4. Stier H, Bischoff SC (2017). [Saccharomyces boulardii CNCM I-745 influences the gut-associated immune system].. MMW Fortschritte der Medizin. DOI PubMed