Saccharomyces boulardii CNCM I-1079 - Clinical Research Data Summary

Saccharomyces boulardii CNCM I-1079 Probiotic Yeast

Saccharomyces boulardii CNCM I-1079 is a clinically studied ingredient used in the following Silver Fern™ Brand product:

Introduction

Saccharomyces boulardii CNCM I-1079 is a well-studied probiotic yeast supported by a large body of human clinical and mechanistic research. Unlike many bacterial probiotics, S. boulardii does not permanently colonize the gastrointestinal tract and is naturally resistant to antibiotics, allowing it to remain active during periods when microbial balance may be challenged, including during antibiotic use. Because it functions as a transient organism, it can interact with the gut environment without permanently altering the resident microbiota.*

Clinical research shows S. boulardii supports digestive balance, helps maintain normal bowel function, and promotes gastrointestinal comfort across diverse populations. It has also been shown to support microbiome stability and gut resilience during periods of dietary, microbial, or environmental stress. The organism has been widely studied in both adults and children and has a long history of safe use in healthy individuals.*

Mechanistic research suggests S. boulardii supports intestinal barrier integrity, promotes healthy immune signaling within the gut, and helps maintain a balanced microbial ecosystem. Many of these effects are mediated through bioactive compounds released by the yeast, allowing it to exert functional benefits without requiring long-term colonization.*

These are the studies for Saccharomyces boulardii CNCM I-1079. Below, we provided a summary of each key data for each study, along with a link to the complete clinical research.

  1. Summary of Study 1 – Full Study: https://pubmed.ncbi.nlm.nih.gov/22423260/
  2. Summary of Study 2 – Full Study: https://pmc.ncbi.nlm.nih.gov/articles/PMC4542552/
  3. Summary of Study 3 – Full Study: https://pubmed.ncbi.nlm.nih.gov/26216624/
  4. Summary of Study 4 – Full Study: https://pubmed.ncbi.nlm.nih.gov/19070525/
  5. Summary of Study 5 – Full Study: https://pubmed.ncbi.nlm.nih.gov/24614141/
  6. Summary of Study 6 – Full Study: https://pubmed.ncbi.nlm.nih.gov/25898944/
  7. Summary of Study 7 – Full Study: https://pubmed.ncbi.nlm.nih.gov/25893960/
  8. Summary of Study 8 – Full Study: https://pmc.ncbi.nlm.nih.gov/articles/PMC5027949/
  9. Summary of Study 9 – Full Study: https://pubmed.ncbi.nlm.nih.gov/28082805/
  10. Summary of Study 10 – Full Study: https://pubmed.ncbi.nlm.nih.gov/33811908/
  11. Summary of Study 11 – Full Study: https://pubmed.ncbi.nlm.nih.gov/27876597/

Ingredient Manufacturer Link: https://www.sboulardiibylallemand.com/



Study 1 Summary

Complete Study Information: https://pubmed.ncbi.nlm.nih.gov/22423260/

Efficacy and Safety of the Probiotic Saccharomyces boulardii for Gastrointestinal Health
Kelesidis T, Pothoulakis C. Therapeutic Advances in Gastroenterology. 2012;5(2):111–125.

This peer-reviewed clinical review summarizes findings from randomized controlled trials, meta-analyses, and mechanistic human studies investigating S. boulardii and its role in supporting gastrointestinal health and microbial balance. The review evaluates clinical evidence, biological mechanisms, and safety considerations across a range of digestive contexts.

Key Findings (What the Study Showed)

  • S. boulardii was associated with improved maintenance of normal bowel function and digestive comfort during periods of microbial disruption, including during antibiotic use
  • Clinical and translational research suggests S. boulardii helps support microbial balance and a stable intestinal environment during digestive stress
  • Human studies in both adults and children observed improvements in digestive comfort and recovery of normal bowel patterns
  • Mechanistic research indicates support for intestinal barrier integrity, interaction with microbial toxins and metabolites, and balanced immune signaling within the gut
  • Generally well tolerated in healthy populations; rare safety concerns reported primarily in severely immunocompromised individuals

Why This Study Matters

The authors conclude that S. boulardii is one of the most extensively studied probiotic yeasts, with substantial clinical and mechanistic evidence supporting digestive balance, microbiome stability, and gastrointestinal resilience. This review is frequently cited because it evaluates the evidence across multiple study types while distinguishing well-supported findings from areas where additional research is needed.*

Reference Link: https://pubmed.ncbi.nlm.nih.gov/22423260/



Study 2 Summary

Complete Study Information: https://pmc.ncbi.nlm.nih.gov/articles/PMC4542552/

Saccharomyces boulardii CNCM I-745 and Intestinal Microbiota Dynamics
Moré MI, Swidsinski A. Clinical and Experimental Gastroenterology. 2015;8:237–255.

This peer-reviewed clinical review evaluated human research investigating S. boulardii CNCM I-745 and its role in supporting gut microbiota balance during periods of gastrointestinal disturbance, reviewing RCTs, observational studies, and mechanistic research including FISH and 16S rRNA microbiological analyses.

Key Findings (What the Study Showed)

  • S. boulardii may help support a balanced intestinal microbiota during periods of temporary disruption
  • Research suggests support for beneficial microbial metabolic processes including short-chain fatty acid production
  • Mechanistic evidence indicates support for intestinal barrier integrity and mucus layer stability
  • Greatest influence observed during periods of gut physiological stress; minimal impact on stable, healthy microbial communities
  • Generally well tolerated in adult and pediatric populations; rare safety concerns in severely immunocompromised individuals

Why This Study Matters

This review highlights a distinct functional model: rather than permanently colonizing the gut, S. boulardii acts as a transient organism that interacts with the gut ecosystem and supports the body's natural ability to maintain microbial balance and digestive resilience — particularly when the system is under challenge.*

Reference Link: https://pmc.ncbi.nlm.nih.gov/articles/PMC4542552/



Study 3 Summary

Complete Study Information: https://pubmed.ncbi.nlm.nih.gov/26216624/

Saccharomyces boulardii and Digestive Outcomes During Antibiotic Use: A Systematic Review and Meta-Analysis
Szajewska H, Kołodziej M. Alimentary Pharmacology & Therapeutics. 2015.

This systematic review and meta-analysis evaluated 21 randomized controlled trials (4,780 participants) investigating S. boulardii supplementation during antibiotic use, assessed using Cochrane and GRADE methodologies across both adult and pediatric populations.

Key Findings (What the Study Showed)

  • Across pooled analyses, S. boulardii was associated with improved maintenance of normal bowel function during antibiotic use
  • Results were consistent in both children and adults across 21 randomized controlled trials
  • Findings support the role of S. boulardii in helping maintain microbial balance during antibiotic exposure
  • Well tolerated across studies with no meaningful differences in adverse events vs. control groups

Why This Study Matters

This meta-analysis evaluates a specific probiotic strain across 21 high-quality human trials, providing a strong and reproducible evidence base for supporting digestive function during periods of microbial disruption. It reinforces the importance of strain-specific research when evaluating probiotic efficacy.*

Reference Link: https://pubmed.ncbi.nlm.nih.gov/26216624/



Study 4 Summary

Complete Study Information: https://pubmed.ncbi.nlm.nih.gov/19070525/

Evaluation of Probiotic Use in Pediatric Gastrointestinal Health: A Randomized Controlled Trial
Terán CG et al. International Journal of Infectious Diseases. 2009;13:518–523.

This prospective, randomized, single-blind, controlled trial evaluated a mixed probiotic formulation including S. boulardii in 75 hospitalized children (28 days–24 months old) with confirmed rotavirus-associated gastrointestinal disturbance, comparing outcomes against standard care and a pharmaceutical comparator.

Study Design Highlights

  • Study design: Prospective, randomized, single-blind, controlled trial
  • Participants: 75 hospitalized children (28 days–24 months); 25 per group
  • Groups: Nitazoxanide (15 mg/kg/day × 3 days), mixed probiotics (L. acidophilus, L. rhamnosus, B. longum, S. boulardii; 1 g twice daily × ~5 days), control (rehydration therapy alone)
  • Primary outcomes: Duration of gastrointestinal disturbance, duration of hospitalization

Key Findings (What the Study Showed)

Duration of Digestive Disturbance

  • Probiotics: Median 48 hours
  • Nitazoxanide: Median 54 hours
  • Control: Median 79 hours

Duration of Hospitalization

  • Probiotics: Median 72 hours
  • Nitazoxanide: Median 81 hours
  • Control: Median 108 hours

Overall clinical outcomes between probiotics and nitazoxanide were similar with no statistically significant difference. Probiotics were well tolerated with no serious adverse events reported.

Why This Study Matters

This study demonstrates that probiotic therapy (including S. boulardii) significantly improved clinical outcomes compared to control, achieving results comparable to a pharmaceutical comparator in hospitalized children. It supports probiotics as an effective, safe, and accessible approach for supporting digestive function during acute gastrointestinal disturbance.*

Reference Link: https://pubmed.ncbi.nlm.nih.gov/19070525/



Study 5 Summary

Complete Study Information: https://pubmed.ncbi.nlm.nih.gov/24614141/

Evidence-Based Evaluation of Probiotic Strains in Pediatric Digestive Health
Szajewska H et al. ESPGHAN Position Paper. Journal of Pediatric Gastroenterology and Nutrition. 2014;58(4):531–539.

This evidence-based position paper from ESPGHAN (European Society for Pediatric Gastroenterology, Hepatology, and Nutrition) reviewed human clinical research on probiotic strains in infants and children using systematic review methodology and GRADE criteria.

Key Findings (What the Study Showed)

  • Among strains evaluated, Saccharomyces boulardii and Lactobacillus rhamnosus GG had the most consistent body of human clinical research supporting digestive function and gastrointestinal balance in pediatric populations
  • The guideline emphasized that probiotic benefits are strain-specific — findings cannot be generalized across other organisms or formulations
  • Many probiotic strains reviewed did not meet the same level of evidence, reinforcing the need for careful strain selection based on human clinical data
  • Probiotics included were generally well tolerated in healthy pediatric populations

Why This Study Matters

This position paper applies rigorous, evidence-based standards to probiotic evaluation and identifies S. boulardii as one of only a limited number of strains with a sufficiently consistent body of human evidence. It reinforces that probiotic efficacy depends on strain identity, quality, and clinical validation.*

Reference Link: https://pubmed.ncbi.nlm.nih.gov/24614141/



Study 6 Summary

Complete Study Information: https://pubmed.ncbi.nlm.nih.gov/25898944/

Saccharomyces boulardii and Gastrointestinal Tolerance During Antibiotic Therapy: A Systematic Review and Meta-Analysis
Szajewska H, Horvath A, Kołodziej M. Alimentary Pharmacology & Therapeutics. 2015;41:1237–1245.

This systematic review and meta-analysis evaluated 11 randomized controlled trials (~2,200 participants) investigating S. boulardii supplementation during antibiotic-based therapy, assessing digestive tolerance, gastrointestinal comfort, and safety outcomes using GRADE methodology.

Key Findings (What the Study Showed)

  • S. boulardii supplementation was associated with improved gastrointestinal tolerance during antibiotic-based regimens
  • Participants receiving S. boulardii experienced fewer gastrointestinal complaints including disturbances in bowel patterns and upper digestive discomfort vs. controls
  • Findings were consistent across adult and pediatric populations with no significant variability between studies
  • Well tolerated with no increase in adverse events or treatment discontinuation vs. controls

Why This Study Matters

This meta-analysis across 11 randomized controlled trials demonstrates consistent evidence that S. boulardii supports gastrointestinal comfort and tolerance during antibiotic-based therapies — a period commonly associated with temporary digestive disruption.*

Reference Link: https://pubmed.ncbi.nlm.nih.gov/25898944/



Study 7 Summary

Complete Study Information: https://pubmed.ncbi.nlm.nih.gov/25893960/

Effects of Saccharomyces boulardii on Lipid-Related Biomarkers: A Pilot Clinical Study
Ryan JJ et al. Journal of Alternative and Complementary Medicine. 2015;21(5):288–293.

This open-label pilot study evaluated the effects of S. boulardii CNCM I-1079 (~112 billion CFU/day) on lipid-related biomarkers in 11 completing adults with elevated cholesterol over 8 weeks, assessing standard lipid markers and advanced lipoprotein particle profiles at baseline, week 4, and week 8.

Key Findings (What the Study Showed)

  • Supplementation was associated with changes in specific lipoprotein particle markers involved in lipid transport and metabolism
  • Traditional lipid markers (total cholesterol, LDL-C, HDL-C, triglycerides) remained stable throughout the study
  • Other measured biomarkers related to metabolic and cardiovascular health remained largely unchanged
  • Well tolerated with high compliance and no serious adverse events

Why This Study Matters

This pilot study — the only one specifically evaluating the CNCM I-1079 strain used in Silver Fern™ Brand's product — explores a novel area of probiotic research examining how a well-characterized yeast may interact with lipid metabolism through microbiome-related mechanisms. It highlights the importance of looking beyond traditional lipid markers when evaluating metabolic health.*

Reference Link: https://pubmed.ncbi.nlm.nih.gov/25893960/



Study 8 Summary

Complete Study Information: https://pmc.ncbi.nlm.nih.gov/articles/PMC5027949/

Influence of Saccharomyces boulardii CNCM I-745 on Gut-Associated Immune Function
Stier H, Bischoff SC. Clinical and Experimental Gastroenterology. 2016;9:269–279.

This peer-reviewed mechanistic review integrates findings from human clinical studies, animal models, and cellular studies to characterize how S. boulardii interacts with gut-associated immune pathways and the intestinal environment.

Key Findings (What the Study Showed)

  • S. boulardii interacts with both innate and adaptive immune pathways, supporting normal immune activity within the gastrointestinal tract
  • Studies suggest S. boulardii can interact with microbial byproducts and signaling pathways, helping to maintain a balanced intestinal ecosystem
  • Evidence across multiple models indicates support for structural integrity of the intestinal lining including tight junction function and mucosal barrier stability
  • Many observed effects are mediated through bioactive compounds released by the yeast, including small molecules and cell wall components interacting with immune and epithelial signaling pathways

Why This Study Matters

This review provides a detailed mechanistic framework for how a non-colonizing probiotic yeast can influence the gut environment. S. boulardii works through host-directed mechanisms — supporting normal immune activity and maintaining gastrointestinal balance — rather than acting as a permanent microbial resident.*

Reference Link: https://pmc.ncbi.nlm.nih.gov/articles/PMC5027949/



Study 9 Summary

Complete Study Information: https://pubmed.ncbi.nlm.nih.gov/28082805/

Effects of Saccharomyces Yeasts on Intestinal Motility Under Stress Conditions: A Preclinical Study
West C et al. World Journal of Gastroenterology. 2016.

This preclinical ex vivo study investigated how S. boulardii and related yeast strains influence intestinal motility under acute stress conditions using mouse intestinal tissue (small intestine and colon) with an acute restraint stress model, evaluating live organisms and cell-free supernatants.

Key Findings (What the Study Showed)

  • Acute stress produced measurable changes in intestinal motility including altered contraction patterns and transit dynamics
  • Application of S. boulardii was associated with improvements in motility patterns toward baseline levels, including more coordinated and regulated intestinal contractions
  • Different Saccharomyces strains showed varying effects depending on the region of the intestine
  • Cell-free supernatants reproduced many observed effects, indicating soluble bioactive compounds play a role in gut signaling and motility regulation

Why This Study Matters

This preclinical study highlights a potential connection between probiotic yeast activity and the regulation of gut motility, suggesting S. boulardii may support normal digestive function during periods of physiological stress through mechanisms that do not require long-term colonization.*

Reference Link: https://pubmed.ncbi.nlm.nih.gov/28082805/



Study 10 Summary

Complete Study Information: https://pubmed.ncbi.nlm.nih.gov/33811908/

Effects of Saccharomyces boulardii on Gut–Brain Axis Signaling: A Preclinical Study
Roy Sarkar S et al. Physiology & Behavior. 2021;235:113375.

This preclinical animal study investigated how S. boulardii influences the gut–brain axis under conditions of antibiotic-induced microbiome disruption, examining gut microbial composition, intestinal barrier function, and biochemical markers related to gut–brain signaling.

Key Findings (What the Study Showed)

  • Antibiotic exposure altered gut microbial composition, intestinal barrier function, and signaling pathways associated with gut–brain communication
  • S. boulardii supplementation was associated with improvements in microbial composition and diversity following disruption
  • Improvements observed in markers related to intestinal barrier integrity and reductions in signaling associated with physiological stress responses
  • Findings suggest S. boulardii may influence biochemical pathways involved in communication between the gastrointestinal system and the central nervous system

Why This Study Matters

This preclinical study highlights the interconnected relationship between the gut microbiome and broader physiological systems, suggesting probiotic yeast may play a role in supporting communication between the gut and other systems during periods of microbial disruption. Results are based on preclinical models and provide mechanistic insight.*

Reference Link: https://pubmed.ncbi.nlm.nih.gov/33811908/



Study 11 Summary

Complete Study Information: https://pubmed.ncbi.nlm.nih.gov/27876597/

Synbiotic-Supported Colon-Targeted Delivery Systems: A Preclinical Study
Kaur R et al. International Journal of Biological Macromolecules. 2017;95:438–450.

This preclinical animal study evaluated how a synbiotic approach combining probiotics (including S. boulardii) with prebiotic fibers influenced microbiome activity and colon-targeted delivery dynamics in an animal model of gastrointestinal disturbance.

Key Findings (What the Study Showed)

  • Microbial activity plays an important role in supporting colon-targeted delivery systems that rely on enzymatic processes within the gut environment
  • The inclusion of probiotic organisms including S. boulardii was associated with improved microbial activity and a more favorable intestinal environment
  • The combination of prebiotics and probiotics showed complementary effects supporting both microbial substrate availability and microbial function
  • Findings suggest that supporting the microbiome may influence factors related to intestinal structure and function

Why This Study Matters

This study highlights the relationship between the gut microbiome and gastrointestinal function, reinforcing the concept that maintaining microbial balance may play a role in supporting normal digestive processes and complementary approaches to gut health.*

Reference Link: https://pubmed.ncbi.nlm.nih.gov/27876597/

Big-Picture Integration with Other Studies

  • Study 1: Narrative review confirming digestive balance, microbiome stability, and GI resilience across multiple human RCTs and meta-analyses.
  • Study 2: Clinical review confirming microbiome balance support, SCFA production, and intestinal barrier integrity during periods of GI disruption.
  • Study 3: Meta-analysis of 21 RCTs (4,780 participants) supporting digestive function during antibiotic use consistently across adults and children.
  • Study 4: Randomized controlled pediatric trial showing probiotic therapy (including S. boulardii) reduced digestive disturbance duration to median 48 hours vs. 79 hours control.
  • Study 5: ESPGHAN evidence-based position paper identifying S. boulardii as one of the most substantiated probiotic strains in pediatric digestive research.
  • Study 6: Meta-analysis of 11 RCTs (~2,200 participants) supporting GI tolerance during antibiotic-based therapy consistently across populations.
  • Study 7: Pilot clinical study of the specific CNCM I-1079 strain showing changes in lipoprotein particle markers without altering standard lipid measures.
  • Study 8: Mechanistic review detailing immune signaling support, intestinal barrier integrity, and tight junction function through bioactive yeast compounds.
  • Study 9: Preclinical ex vivo study supporting more balanced intestinal motility patterns during acute stress conditions through bioactive compound release.
  • Study 10: Preclinical study suggesting gut–brain axis signaling support and microbiome restoration following antibiotic-induced disruption.
  • Study 11: Preclinical synbiotic study supporting microbial activity and colon-targeted delivery mechanisms through microbiome balance.

Saccharomyces boulardii CNCM I-1079 Ingredient Summary & Real-World Relevance

Saccharomyces boulardii CNCM I-1079 is distinct from traditional bacterial probiotics. As a probiotic yeast, it is naturally resistant to antibiotics, does not permanently colonize the gastrointestinal tract, and interacts with the gut environment through multiple complementary mechanisms — including support for microbial balance, intestinal barrier integrity, and immune signaling.*

Human clinical research, meta-analyses, and mechanistic studies demonstrate its role in supporting digestive function, microbiome stability, immune activity, and broader physiological processes linked to the gut environment. Importantly, its effects are context-dependent — supporting balance when the system is challenged while remaining compatible with a stable, healthy microbiome.*

From a practical use perspective, S. boulardii is shelf-stable, compatible with antibiotic use, fast-acting, and well tolerated across a wide range of individuals. Its combination of clinical research, mechanistic understanding, and real-world usability makes it a versatile and widely studied probiotic organism for supporting digestive and microbiome health.*

Ingredient Manufacturer Link: https://www.sboulardiibylallemand.com/

Saccharomyces boulardii CNCM I-1079 is a clinically studied ingredient used in the following Silver Fern™ Brand product:

*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.