Probiotic Recommendations for Diarrhea
Probiotic preparations may be offered to reduce symptom severity and duration in immunocompetent adults and children with infectious or antimicrobial-associated diarrhea, with Lactobacillus rhamnosus GG or Saccharomyces boulardii being the preferred strains. 1
Recommended Probiotic Strains
First-Line Options
Lactobacillus rhamnosus GG (LGG): Reduces diarrhea duration by approximately 1 day and has the strongest evidence base for both infectious gastroenteritis and antibiotic-associated diarrhea 2
Saccharomyces boulardii: Equally effective as LGG in reducing diarrhea duration by approximately 1 day, with evidence suggesting it may be the most effective strain with the fewest adverse effects, particularly for antibiotic-associated diarrhea 2, 3
Alternative Strains
Lactobacillus reuteri: Demonstrated efficacy in pediatric acute diarrhea, particularly for viral etiologies 4
Bifidobacterium species: May be effective as prophylactic agents, particularly in infants 4
Expected Clinical Benefits
Duration reduction: Probiotics decrease mean diarrhea duration by approximately 25 hours (95% CI: 16-34 hours) 1
Symptom improvement: Reduction in stool frequency noted by the second day of symptoms 1
Risk reduction: Decreased risk of diarrhea lasting >4 days 1
Greatest efficacy: Viral etiology diarrhea shows better response than bacterial causes 1
Dosing Considerations
Lactobacillus rhamnosus GG: 10^10 colony-forming units per day 1
Saccharomyces boulardii: Dosing varies by formulation; follow manufacturer guidance 1
Duration: Continue throughout antibiotic course and for several days after completion for antibiotic-associated diarrhea 1
Critical Safety Considerations
Contraindications
Avoid in critically ill or severely immunocompromised patients: Case reports document bacteremia or fungemia with molecularly matched probiotic isolates in these populations 1, 5
Not for immunocompromised hosts: Use with extreme caution or avoid entirely 5
Important Caveats
Not a substitute for rehydration: Probiotics are adjunctive therapy only; proper fluid and electrolyte replacement remains the cornerstone of diarrhea management 5, 6
Strain-specific efficacy: Effects are not generalizable across all probiotic preparations; specific strains listed above have the strongest evidence 5
Dose-dependent effects: Efficacy varies with dosing regimens 5
Monitoring and Follow-Up
Assess response at 3 days: Monitor for reduction in stool frequency and improvement in consistency 5
Reassess if no improvement: If symptoms persist beyond 3 days without improvement, reevaluate the underlying cause 5
Consider alternative diagnoses after 14 days: Persistent symptoms warrant evaluation for non-infectious causes including lactose intolerance, inflammatory bowel disease, or irritable bowel syndrome 5
Clinical Context by Etiology
Infectious Gastroenteritis
- Strong evidence supports probiotic use as active treatment in addition to rehydration 2
- Most effective for rotavirus and other viral diarrheas 1
Antibiotic-Associated Diarrhea
- Solid evidence for prevention when started within 48 hours of antibiotic initiation 2
- Continue for 5 days after antibiotic completion 7
- Saccharomyces boulardii I-745 may be prioritized for this indication 3
Clostridium difficile-Associated Diarrhea
- Probiotics reduce risk of developing C. difficile diarrhea by 64% when given with antibiotics 1
- Both safe and effective for prevention 1
Practical Ordering Guidance
When ordering probiotics, specify: