Bacillus clausii SC-109 - Clinical Research Data Summary

B. clausii SC-109 Spore-Forming Probiotic Strain

B. clausii SC-109 is a clinically studied ingredient used in the following Silver Fern™ Brand products:

Introduction

Bacillus clausii SC-109 is a spore-forming probiotic strain known for its stability and ability to function under challenging digestive conditions. In its spore form, SC-109 can withstand stomach acid, bile salts, digestive enzymes, and low-oxygen environments, allowing it to reach the intestine intact where it can become metabolically active. Laboratory studies show that B. clausii spores tolerate simulated gastrointestinal conditions and can germinate in gut-like environments — features that help distinguish spore-forming probiotics from many traditional non-spore probiotic organisms.*

Research on Bacillus clausii strains suggests they may help support healthy immune system function and maintain communication between the gut microbiome and the immune system. Studies examining immune signaling markers indicate that these probiotics can interact with regulatory pathways involved in normal immune responses and mucosal health. Additional research suggests that B. clausii may contribute to maintaining microbial balance and supporting the integrity of the intestinal environment.*

At the cellular level, studies evaluating intestinal signaling pathways indicate that B. clausii strains may influence processes associated with immune regulation, epithelial maintenance, and normal cellular turnover in the gut.*

These are the studies for Bacillus clausii SC-109. 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/17105550/
  2. Summary of Study 2 – Full Study: https://pubmed.ncbi.nlm.nih.gov/18360611/
  3. Summary of Study 3 – Full Study: https://pubmed.ncbi.nlm.nih.gov/15813820/
  4. Summary of Study 4 – Full Study: https://pubmed.ncbi.nlm.nih.gov/19352343/
  5. Summary of Study 5 – Full Study: https://pubmed.ncbi.nlm.nih.gov/16093873/

Ingredient Manufacturer Link: https://www.novonesis.com/en



Study 1 Summary

Complete Study Information: https://pubmed.ncbi.nlm.nih.gov/17105550/

Tolerance of Bacillus clausii to Simulated Gastrointestinal Conditions
Cenci, G. et al. Journal of Applied Microbiology. 2006;101:1208–1215.

This controlled laboratory study evaluated how Bacillus clausii spores and vegetative cells respond to conditions designed to mimic human digestive transit, including stomach acidity, bile exposure, oxygen limitation, and combined digestive stressors.

Study Design Highlights

  • Study type: Controlled laboratory study (in vitro)
  • Organisms: Four probiotic B. clausii strains, reference B. clausii strains, and B. subtilis controls
  • Conditions simulated: Acid exposure (pH 2–6), conjugated and free bile salts (up to 1%), sequential acid–bile exposure, microaerophilic and anaerobic growth conditions
  • Measured outcomes: Spore germination, vegetative cell growth, growth rate and lag time, final cell yield, comparative tolerance vs. B. subtilis

Key Findings (What the Study Showed)

1. Survival and Germination After Acid Exposure

B. clausii spores tolerated acidic conditions comparable to those found in the stomach (pH 2 for up to two hours) and retained their ability to germinate and resume growth when transferred to bile-containing environments.

2. Tolerance to Bile Salts

Vegetative cells grew in the presence of conjugated bile salts at 0.5–1.0%. Although growth was temporarily delayed, cells remained viable. Bile tolerance of B. clausii strains was similar to or greater than the reference strain and exceeded that of B. subtilis.

3. Survival Under Combined Digestive Stress

When spores were exposed sequentially to acid followed by bile salts — simulating digestive transit — temporary stress was observed, followed by recovery of growth within 24 hours.

4. Adaptation to Low-Oxygen Conditions

All B. clausii strains demonstrated growth under microaerophilic conditions, and several strains grew under anaerobic conditions when nitrate was present, consistent with environments found in portions of the digestive tract.

Benefits of B. clausii SC-109 Demonstrated by This Study

Based directly on the laboratory findings, B. clausii was shown to:
✓ Tolerate highly acidic conditions (pH 2) for up to 2 hours without loss of viability
✓ Germinate and resume growth following sequential acid and bile exposure
✓ Tolerate bile salt concentrations of 0.5–1.0%
✓ Demonstrate bile tolerance exceeding that of B. subtilis reference strains
✓ Grow under low-oxygen and anaerobic conditions representative of the intestine

Why This Study Matters

This research helps explain why spore-forming probiotics such as B. clausii are able to remain stable during digestive transit. The spore structure allows the organism to tolerate multiple digestive stressors simultaneously while maintaining viability — a key advantage over many non-spore-forming probiotic organisms.*

Reference Link: https://pubmed.ncbi.nlm.nih.gov/17105550/



Study 2 Summary

Complete Study Information: https://pubmed.ncbi.nlm.nih.gov/18360611/

Clinical Research Evaluating Bacillus clausii Supplementation in Children
Marseglia, G.L. et al. Therapeutics and Clinical Risk Management. 2007;3(1):13–17.

This randomized, single-blind pilot clinical study evaluated the effects of daily supplementation with B. clausii spores (2 billion spores per vial, twice daily) in 80 children aged 3–6 years over three months of supplementation followed by three months of follow-up (40 probiotic, 40 control).

Study Design Highlights

  • Study design: Randomized, single-blind, controlled pilot study
  • Participants: 80 children (ages 3–6); 40 probiotic, 40 control
  • Dose: B. clausii spores — 1 vial (2 billion spores) twice daily
  • Duration: 3 months supplementation + 3 months follow-up

Key Findings (What the Study Showed)

  • Children receiving B. clausii supplementation experienced differences in the duration of respiratory-related health episodes compared with the control group
  • Similar trends were observed during the follow-up phase after supplementation ended
  • A trend toward fewer respiratory health episodes was noted in the probiotic group compared with controls
  • The probiotic was well tolerated; no participants discontinued due to adverse events; reported events were mild and self-limited

Benefits of B. clausii SC-109 Demonstrated by This Study

Based directly on the clinical findings, B. clausii supplementation in children was shown to:
✓ Be associated with differences in respiratory health episode duration vs. control
✓ Show trends toward fewer respiratory health episodes during the supplementation period
✓ Demonstrate carry-over effects during the follow-up phase
✓ Be well tolerated in children ages 3–6 with no discontinuations

Why This Study Matters

This clinical research contributes to the growing body of evidence examining how probiotics may interact with immune system and overall health in children. Because B. clausii forms stable spores capable of surviving digestive transit, it has been studied as a probiotic that may support normal immune function and overall microbial balance.*

Reference Link: https://pubmed.ncbi.nlm.nih.gov/18360611/



Study 3 Summary

Complete Study Information: https://pubmed.ncbi.nlm.nih.gov/15813820/

Clinical Research Evaluating Bacillus clausii Supplementation and Immune-Related Outcomes in Children
Ciprandi G., Vizzaccaro A., Cirillo I., Tosca M.A. Allergy. 2005;60:702–703.

This randomized pilot study evaluated B. clausii supplementation (2 billion spores per vial, 3 vials per day) in 20 children aged 12–15 over a three-week period, comparing outcomes against standard care alone. Laboratory assessments were blinded.

Study Design Highlights

  • Study design: Randomized pilot study
  • Participants: 20 children (ages 12–15)
  • Groups: Standard care + B. clausii (3 vials/day) vs. standard care alone
  • Duration: 3 weeks
  • Measured outcomes: Total nasal symptom score (TSS), nasal eosinophil counts, days requiring standard care medication

Key Findings (What the Study Showed)

  • Participants receiving B. clausii showed differences in symptom score measurements during the study period vs. control
  • The probiotic group demonstrated changes in nasal eosinophil measurements vs. controls — eosinophils are immune cells commonly evaluated in studies examining mucosal immune responses
  • Differences observed in the number of days participants used standard care medication during the study period
  • No adverse effects reported; probiotic supplementation well tolerated by all participants

Benefits of B. clausii SC-109 Demonstrated by This Study

Based directly on the study findings, B. clausii supplementation was shown to:
✓ Influence immune-related observations including nasal symptom scores and eosinophil markers
✓ Support differences in standard care medication usage during the study period
✓ Be well tolerated with no adverse effects in children ages 12–15

Why This Study Matters

This research contributes to the broader body of research examining how probiotic organisms may interact with immune pathways and mucosal health. The eosinophil findings provide insight into how B. clausii may interact with mucosal immune signaling in a pediatric research context.*

Reference Link: https://pubmed.ncbi.nlm.nih.gov/15813820/



Study 4 Summary

Complete Study Information: https://pubmed.ncbi.nlm.nih.gov/19352343/

Clinical Research Evaluating Bacillus clausii Supplementation and Microbial Balance Markers
Gabrielli M., Lauritano E.C., Scarpellini E., et al. The American Journal of Gastroenterology. 2009;104:1327–1328.

This prospective, open-label clinical study evaluated B. clausii (Enterogermina®) supplementation (2 × 10⁹ spores per vial, 3 vials daily) in 40 adult outpatients (mean age 30 ± 15 years) over one month, assessing glucose breath test measurements and tolerability.

Study Design Highlights

  • Study design: Prospective, open-label clinical study
  • Participants: 40 adult outpatients (mean age 30 ± 15 years)
  • Dose: 2 × 10⁹ spores per vial, 3 vials per day
  • Duration: 1 month; repeat breath test conducted 1 month after completion
  • Measured outcomes: Glucose breath test measurements, compliance, safety and tolerability

Key Findings (What the Study Showed)

  • A portion of participants showed changes in glucose breath test measurements following the supplementation period compared with baseline
  • High participant compliance with the supplementation protocol throughout the study
  • Well tolerated: no study dropouts, only one mild adverse event, no serious adverse events
  • Authors noted additional controlled research would be useful to further evaluate these findings

Benefits of B. clausii SC-109 Demonstrated by This Study

Based directly on the clinical findings, B. clausii supplementation was shown to:
✓ Be associated with changes in breath test measurements related to microbial activity
✓ Achieve high participant compliance over one month of use
✓ Demonstrate excellent tolerability with only one mild adverse event and no discontinuations

Why This Study Matters

Clinical research on spore-forming probiotics such as B. clausii continues to explore how these organisms interact with the digestive microbiome. Because Bacillus spores are stable and capable of surviving digestive transit, they are frequently studied for their ability to remain viable in the gastrointestinal environment and interact with microbial communities.*

Reference Link: https://pubmed.ncbi.nlm.nih.gov/19352343/



Study 5 Summary

Complete Study Information: https://pubmed.ncbi.nlm.nih.gov/16093873/

Human Study Evaluating the Effects of Bacillus clausii on Intestinal Gene Expression
Di Caro S. et al. European Journal of Gastroenterology & Hepatology. 2005;17:951–960.

This human mechanistic study used DNA microarray analysis (~22,000 genes, Affymetrix Human U133A) to examine how B. clausii supplementation (3 vials/day, 2 × 10⁹ spores each) for 30 days influenced gene expression patterns in the small intestinal mucosa of 6 adult male participants (mean age 38 ± 5 years). Duodenal biopsies were collected before and after intervention; selected genes were validated by real-time RT-PCR.

Study Design Highlights

  • Study type: Human mechanistic study with genome-wide gene expression profiling
  • Participants: 6 adult males (mean age 38 ± 5 years)
  • Dose: 3 vials/day (2 × 10⁹ spores each)
  • Duration: 30 days
  • Comparison: Proton pump inhibitor therapy alone (control condition)
  • Analysis: Affymetrix Human U133A microarray (~22,000 genes); RT-PCR validation

Key Findings (What the Study Showed)

Changes in Intestinal Gene Expression

  • 92 genes showed increased expression following supplementation
  • 265 genes showed decreased expression
  • Measurable shifts in intestinal gene signaling pathways were observed

Pathways Related to Immune Signaling

Several genes involved in immune-related signaling pathways were affected, including those associated with cytokine receptors and immune communication networks, suggesting probiotic interaction with normal immune response pathways within the intestinal environment.

Pathways Related to Epithelial Maintenance

Changes were observed in genes associated with cellular adhesion, epithelial structure, and tissue organization — pathways commonly studied in research examining maintenance of the intestinal lining.

Cellular Signaling and Regulatory Pathways

Additional gene expression changes were noted in pathways involved in cellular stress responses, programmed cell turnover, and regulatory signaling processes within intestinal tissue.

Benefits of B. clausii SC-109 Demonstrated by This Study

Based directly on the mechanistic findings, B. clausii supplementation was shown to:
✓ Produce measurable changes in intestinal mucosal gene expression (357 genes total)
✓ Influence immune-related signaling pathways including cytokine receptor expression
✓ Influence epithelial maintenance and cellular adhesion pathways
✓ Influence cellular stress response and regulatory pathways within intestinal tissue
✓ Demonstrate molecular-level interaction between probiotic and host intestinal tissue

Why This Study Matters

Most probiotic research focuses on microbiome composition or clinical observations. This study adds another layer of understanding by examining how probiotic organisms may interact with intestinal tissue at the molecular level. Because this study examined molecular signaling rather than clinical outcomes, further research is needed to understand how these findings relate to broader health effects.*

Reference Link: https://pubmed.ncbi.nlm.nih.gov/16093873/

Big-Picture Integration with Other Studies

  • Study 1: Laboratory research demonstrating that B. clausii spores can tolerate simulated stomach acid (pH 2, 2 hours) and bile exposure (0.5–1.0%), germinate under gut-like conditions, and grow under low-oxygen environments — supporting probiotic stability during digestive transit.
  • Study 2: Randomized pilot clinical study in 80 children (ages 3–6) showing B. clausii was associated with differences in respiratory health episode duration and was well tolerated over 3 months with no discontinuations.
  • Study 3: Randomized pilot study in children (ages 12–15) evaluating how B. clausii supplementation influenced immune-related markers including nasal symptom scores and eosinophil measurements alongside standard care.
  • Study 4: Prospective open-label clinical study in 40 adults showing B. clausii was associated with changes in glucose breath test measurements related to microbial activity, with high compliance and excellent tolerability.
  • Study 5: Human mechanistic gene expression study demonstrating that B. clausii supplementation influenced 357 intestinal genes involved in immune signaling, epithelial maintenance, and cellular regulatory pathways in small intestinal mucosa.

Together, these studies suggest that B. clausii is a resilient spore-forming probiotic capable of surviving digestive transit and interacting with the intestinal environment. Its stability allows it to reach the intestine in viable form, where it may help support microbial balance and normal immune system activity within the digestive tract.*

B. clausii SC-109 Ingredient Summary & Real-World Relevance

Bacillus clausii forms durable spores that can survive stomach acid and bile, allowing the probiotic to reach the intestine in viable form. After reaching the intestinal environment, the spores can germinate and temporarily interact with the surrounding microbial ecosystem. Compared with many traditional probiotic organisms that may be sensitive to digestive conditions, B. clausii demonstrates strong survivability during gastrointestinal transit.*

Human and mechanistic studies have explored how this spore-forming probiotic may influence immune signaling pathways and microbial balance within the digestive tract. Research examining B. clausii has evaluated its interaction with immune markers, intestinal gene-expression pathways, and respiratory health observations in pediatric populations. Additional clinical research has investigated how supplementation may influence measurements associated with microbial activity in the digestive system while remaining well tolerated.*

These characteristics make B. clausii SC-109 a valuable ingredient for probiotic formulations designed to support digestive health, microbial balance, and normal immune system function.*

Ingredient Manufacturer Link: https://www.novonesis.com/en

B. clausii SC-109 is a clinically studied ingredient used in the following Silver Fern™ Brand products:

*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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