Florastor vs Culturelle: Which Probiotic Is Right for You?
Florastor vs Culturelle: Which Probiotic Is Right for You?
By Dr. Onikepe Adegbola, MD PhD — Johns Hopkins-trained physician-scientist
Florastor and Culturelle are both widely recommended probiotics, but they're fundamentally different organisms targeting different problems. Florastor contains Saccharomyces boulardii — a beneficial yeast, not a bacterium. Culturelle contains Lactobacillus rhamnosus GG — one of the most studied bacterial probiotics. Understanding this distinction is key to choosing the right one.
Key Takeaways
- Florastor (S. boulardii) is a yeast — it's naturally antibiotic-resistant, making it the best choice during or after antibiotic treatment
- Culturelle (L. rhamnosus GG) is a bacterium — excellent for general gut health and preventing infectious diarrhea
- For antibiotic-associated diarrhea specifically, Florastor has the stronger evidence
- For general IBS management, Culturelle has broader supporting data
- Neither contains digestive enzymes — for comprehensive gut support, a combined enzyme + probiotic formula may provide more complete coverage
Quick Comparison
| Feature | Florastor | Culturelle |
|---|---|---|
| Active organism | S. boulardii CNCM I-745 | L. rhamnosus GG |
| Type | Beneficial yeast | Bacterial probiotic |
| CFU | 250mg (5 billion CFU) | 10 billion CFU |
| Antibiotic-resistant | Yes — can be taken during antibiotics | No — antibiotics may kill it |
| Best for | Antibiotic-associated diarrhea, C. diff prevention, traveler's diarrhea | General gut health, IBS, infectious diarrhea prevention |
| Requires refrigeration | No (yeast is heat-stable) | No |
| Dairy/gluten-free | Yes | Yes |
Florastor: The Antibiotic Companion
The standout feature of S. boulardii is that it's a yeast, not a bacterium. This means antibiotics can't kill it. When you're taking amoxicillin, ciprofloxacin, metronidazole, or any other antibiotic, it destroys your beneficial bacteria along with the targeted pathogens. Taking a bacterial probiotic during antibiotics is somewhat counterproductive — the antibiotic kills a significant portion of the probiotic before it can work.
S. boulardii sidesteps this problem entirely. It thrives during antibiotic treatment, maintaining a beneficial presence in your gut while your bacterial population is depleted. A 2015 meta-analysis in the World Journal of Gastroenterology found that S. boulardii reduced antibiotic-associated diarrhea risk by 47%.
It's also the single best-studied probiotic for preventing Clostridioides difficile recurrence — a potentially serious complication of antibiotic use. The ACG gives S. boulardii a conditional recommendation for C. diff prevention.
Culturelle: The Everyday Probiotic
L. rhamnosus GG (LGG) is the most studied bacterial probiotic strain in the world, with over 1,000 published studies. It's a versatile, well-characterized strain with evidence across multiple conditions. For patients who aren't on antibiotics and want a daily probiotic for general gut health or IBS management, LGG is a solid evidence-based choice.
The evidence is strongest for preventing infectious diarrhea (in travelers and children), supporting immune function, and modestly improving IBS symptoms. See our Align vs Culturelle comparison for more on IBS-specific evidence.
Which Should You Choose?
Choose Florastor if:
- You're currently taking antibiotics
- You're about to start an antibiotic course
- You've had C. diff infection and want to prevent recurrence
- You're planning international travel to high-risk areas
- You have recurrent antibiotic-associated diarrhea
Choose Culturelle if:
- You want a daily probiotic for general gut maintenance
- Your primary concerns are IBS symptoms (pain, bloating, irregular bowels)
- You're recovering from a GI infection
- You want immune support during cold/flu season
Consider a Broader Formula if:
- You need enzyme support alongside probiotics (food intolerance, FODMAP sensitivity)
- You want prebiotic, probiotic, AND postbiotic coverage in one product
- A physician-formulated multi-strain probiotic with low FODMAP certification may provide more comprehensive support than either single-strain option
Can You Take Both Together?
Yes — and there's actually a reasonable case for it during antibiotic treatment. Take Florastor during the antibiotic course (since it survives antibiotics), then switch to or add Culturelle after you finish the antibiotics to help rebuild your bacterial population. This sequential approach addresses both the acute and recovery phases.
FAQ
Can I take Florastor while on antibiotics?
Yes — this is its primary advantage. As a yeast, S. boulardii is unaffected by antibacterial antibiotics. Take it at least 2 hours apart from your antibiotic dose for best results.
Is Florastor or Culturelle better for IBS?
Culturelle (LGG) has more direct evidence for IBS symptom improvement. Florastor is better suited for antibiotic-related issues and diarrhea prevention. For IBS specifically, also consider our complete probiotic guide for strain-specific recommendations.
Are there side effects?
Both are generally well-tolerated. Mild gas or bloating during the first few days is normal. Florastor should be avoided in patients with central venous catheters or severely immunocompromised patients due to rare reports of fungemia.
This article is for informational purposes only. Probiotic recommendations should be tailored to your individual health situation. Consult your healthcare provider, especially if you're immunocompromised or have a central line.
