What is the appropriate dose of Bacillus clausii (probiotic spores)?

Medical Advisory BoardAll articles are reviewed for accuracy by our Medical Advisory Board
Educational purpose only • Exercise caution as content is pending human review
Article Review Status
Submitted
Under Review
Approved

Last updated: October 28, 2025View editorial policy

Personalize

Help us tailor your experience

Which best describes you? Your choice helps us use language that's most understandable for you.

Appropriate Dosage of Bacillus clausii Probiotic Spores

The recommended dosage of Bacillus clausii probiotic spores is 4 billion CFU/day for children and 6 billion CFU/day for adolescents and adults for up to 14 days. 1

Dosage Recommendations by Age Group

Children

  • 4 billion spores per day (typically administered as 2 billion spores twice daily) 1, 2
  • For infants and children with acute diarrhea: 2 billion spores per 5 mL bottle, administered twice daily (morning and evening) for 5 days 3
  • For persistent diarrhea in children: Higher dosages of 4-6 ampoules daily (each containing 2 billion CFU/5 mL) have shown significant efficacy 4

Adolescents and Adults

  • 6 billion spores per day (typically administered as 3 billion spores twice daily) 1
  • Duration of treatment typically ranges from 5-14 days depending on the condition being treated 1, 5

Dosage by Clinical Indication

Antibiotic-Associated Diarrhea (AAD) Prevention

  • Adults: 6 billion CFU/day for the duration of antibiotic treatment and up to 7 days after completion 1
  • Children: 4 billion CFU/day during antibiotic treatment and up to 7 days after completion 1

Acute Diarrhea Treatment

  • Children aged 6 months to 5 years: One mini bottle of B. clausii (2 billion spores per 5 mL) twice daily for 5 days 3
  • For community-acquired diarrhea in children: 1-2 vials of B. clausii (each containing 2 billion spores per 5 mL) daily for 5-7 days 5

Persistent Diarrhea Treatment

  • Children: 4-6 ampoules daily (each containing 2 billion CFU/5 mL), which has shown to reduce recovery time by approximately 2 days compared to standard treatment 4

Irritable Bowel Syndrome (IBS)

  • Children aged 6-17 years: Total dose of 4 billion spores/day administered once daily for 8 weeks 2

Administration Guidelines

  • B. clausii spores can be administered orally via suspension, mini bottles, or capsules 1, 3, 5
  • For infants and young children, the contents can be mixed with water, milk, or juice at room temperature 5
  • Administration should ideally be between meals to maximize probiotic survival and colonization 1
  • For patients with feeding tubes, B. clausii can be administered through nasogastric or nasojejunal tubes 6

Clinical Considerations

  • B. clausii is resistant to most commonly used antibiotics, making it suitable for concurrent administration with antibiotic therapy 1
  • The probiotic shows good tolerability with a very low adverse event rate (0.09%) 5
  • Reported adverse events are generally mild to moderate and may include vomiting, erythematous rashes, and stool color changes 5
  • No significant safety concerns have been reported in clinical trials 1, 2, 3, 4, 5

Special Populations

  • Critically ill patients: While specific B. clausii dosing is not established for this population, other probiotics have been studied in ICU settings with various dosing regimens 6
  • Pregnant women: No specific contraindications, but limited data exists on use during pregnancy 1

Remember that B. clausii appears to be most effective when started early in the course of treatment, particularly for diarrheal conditions 4, 5.

Professional Medical Disclaimer

This information is intended for healthcare professionals. Any medical decision-making should rely on clinical judgment and independently verified information. The content provided herein does not replace professional discretion and should be considered supplementary to established clinical guidelines. Healthcare providers should verify all information against primary literature and current practice standards before application in patient care. Dr.Oracle assumes no liability for clinical decisions based on this content.

Have a follow-up question?

Our Medical A.I. is used by practicing medical doctors at top research institutions around the world. Ask any follow up question and get world-class guideline-backed answers instantly.