Is Florastor (Saccharomyces boulardii) probiotic effective for 14 days in a patient taking antibiotics?

Florastor (Saccharomyces boulardii) is Effective During 14-Day Antibiotic Treatment

Florastor (Saccharomyces boulardii) probiotic is recommended for patients taking antibiotics for 14 days to reduce the risk of antibiotic-associated diarrhea and C. difficile infection. 1

Evidence for Effectiveness

Saccharomyces boulardii has strong evidence supporting its use during antibiotic therapy:

• Meta-analyses demonstrate that S. boulardii significantly reduces the risk of antibiotic-associated diarrhea (AAD) from 17.2% to 6.7% 2
• The number needed to treat (NNT) to prevent one case of AAD is 10 2
• S. boulardii can mitigate antibiotic-induced dysbiosis (disruption of gut microbiota) 3
• Unlike bacterial probiotics, S. boulardii is a yeast and therefore not directly affected by antibiotics, making it particularly suitable for administration during antibiotic treatment 4

Timing and Duration

For optimal effectiveness:

• Start Florastor within 48 hours of beginning antibiotic therapy 3
• Continue throughout the 14-day antibiotic course
• For best results, continue Florastor for 7 days after completing antibiotics to help restore normal gut flora 3

Mechanism of Action

Florastor helps prevent antibiotic-associated complications through several mechanisms:

• Competes with pathogenic bacteria
• Modulates local and systemic immune responses
• Improves gut barrier function
• Promotes restoration of normal gut microbiota 1, 3

Specific Benefits During Antibiotic Therapy

1. Reduced risk of antibiotic-associated diarrhea (AAD) 1, 5
2. Prevention of Clostridioides difficile infection 1
3. Fewer gastrointestinal adverse events from antibiotics 3
4. Better tolerance of antibiotic regimens 3
5. Less pronounced microbiota disruption including reduced overgrowth of potentially harmful bacteria like Escherichia 3

Important Considerations

• Efficacy is strain-specific - ensure you're using genuine Saccharomyces boulardii CNCM I-745 (Florastor) 4
• Take Florastor at least 2 hours apart from antibiotic doses
• While generally safe, avoid in severely immunocompromised patients 1
• Not all probiotics are equally effective during antibiotic therapy; S. boulardii has particularly strong evidence 1

Potential Limitations

A 2012 study in elderly hospitalized patients did not show effectiveness in preventing AAD 6, but this contradicts multiple other studies and meta-analyses showing benefit 5, 2. The weight of evidence supports using S. boulardii during antibiotic therapy, particularly in outpatient settings.

Florastor represents one of the most evidence-based approaches to mitigating antibiotic-associated complications and is appropriate for a 14-day course of antibiotics.