Should You Take Probiotics With Antibiotics? A Doctor's Protocol

Should You Take Probiotics With Antibiotics? A Doctor's Protocol

By Dr. Onikepe Adegbola, MD PhD — Johns Hopkins-trained physician-scientist

The short answer is yes — and the evidence is strong enough that I recommend it to virtually all my patients who are prescribed antibiotics. Antibiotic-associated diarrhea (AAD) affects up to 30% of patients, and probiotics reduce that risk by approximately 42% according to a 2012 Cochrane review of 82 studies.

But which probiotic, when to start, and how to time it around your antibiotic doses? Those details matter.

Key Takeaways

• Start probiotics on the same day as your antibiotic — don't wait for symptoms to develop
• Take probiotics at least 2 hours apart from your antibiotic dose
• Saccharomyces boulardii (found in Florastor) is the best choice during antibiotics because it's a yeast — antibiotics can't kill it
• Lactobacillus rhamnosus GG (Culturelle) is also supported, but take it maximally separated from antibiotic doses
• Continue probiotics for at least 1-2 weeks AFTER finishing the antibiotic course
• For comprehensive gut recovery, multi-strain probiotics post-antibiotic help rebuild microbial diversity

My Antibiotic Probiotic Protocol

During Antibiotics (Day 1 to Last Day)

1. Primary: Saccharomyces boulardii — 250-500mg twice daily. Can be taken at any time because antibiotics don't affect it.
2. Optional addition: L. rhamnosus GG — Take at least 2 hours before or after your antibiotic dose to maximize survival.

After Antibiotics (Weeks 1-4)

1. Continue S. boulardii for 1 additional week to maintain protection during the recovery window.
2. Switch to or add a multi-strain probiotic — Advanced Probiotics GI Support helps rebuild the diverse bacterial community that antibiotics disrupted.
3. Support with digestive enzymes — FODMAP digestive enzymes help during the recovery period when your gut's natural enzyme production may be suboptimal.

Why Timing Matters

If you take a bacterial probiotic (like Culturelle) at the same time as your antibiotic, the antibiotic will kill a significant portion of the probiotic bacteria before they can colonize. The 2-hour window gives the probiotic time to pass through the stomach and begin establishing in the intestine before the next antibiotic wave arrives.

S. boulardii doesn't have this timing constraint because it's a yeast, not a bacterium. Antibacterial antibiotics have no effect on yeast. This is the primary reason it's the #1 recommended probiotic during antibiotic treatment.

Which Antibiotics Are Most Likely to Cause Gut Problems?

• Amoxicillin/clavulanate (Augmentin) — ~25% diarrhea rate. Probiotic strongly recommended.
• Clindamycin — High risk for AAD and C. diff. Always use probiotic.
• Fluoroquinolones (Cipro, Levaquin) — Moderate AAD risk. Probiotic recommended.
• Cephalosporins — Moderate risk. Probiotic recommended.
• Azithromycin (Z-pack) — Lower risk but still benefits from probiotic support.

FAQ

Can probiotics reduce antibiotic effectiveness?

No. There's no evidence that probiotics interfere with antibiotic efficacy. The antibiotic targets pathogenic bacteria at the infection site; the probiotic works in the gut. They operate in different areas with different mechanisms.

How long should I take probiotics after antibiotics?

I recommend at least 2-4 weeks after completing the antibiotic course. Some patients benefit from ongoing probiotic use, especially if they have underlying IBS. See our Florastor vs Culturelle comparison for choosing your post-antibiotic probiotic.

What if I already have diarrhea from antibiotics?

Start probiotics immediately. S. boulardii at 500mg twice daily is the evidence-based first-line treatment for existing AAD. If diarrhea is severe, bloody, or accompanied by fever, contact your prescribing physician immediately — you may need C. diff testing.

This article is for educational purposes only. Do not stop prescribed antibiotics without consulting your prescribing physician. If you develop severe diarrhea during antibiotic treatment, seek medical attention promptly.