Probiotic

Lactobacillus rhamnosus GG

Also known as: Culturelle, Culturelle strain, L. rhamnosus, L. rhamnosus GG

Evidence

One of the most researched probiotic strains. Excellent for antibiotic-associated diarrhea and traveler's diarrhea prevention.

Last reviewed June 2026 · Evidence graded from peer-reviewed research, not editorial opinion. Educational only — not medical advice.

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Primary uses

Diarrhea prevention
Antibiotic support
Traveler's health
Immune support

How it works

Strong gut adherence
Immune modulation
Pathogen exclusion

Dosage

Typical range: 10-20 billion CFU daily
Timing: Any time
With food: Either way
Duration: During and after antibiotics
Special populations: Antibiotic users, travelers

Forms

Capsules

Safety

Common side effects

Minimal

Contraindications

Severe immunocompromise

Evidence notes

Most studied probiotic strain

Grade A: Multiple well-designed human trials support the main claims.

Cited research for Lactobacillus rhamnosus GG

Clinical studies referenced across Formulate guides that mention lactobacillus rhamnosus gg. Each links to the full study page with PubMed source + the guides that cite it.

Szajewska et al. (2013)Alimentary Pharmacology & Therapeutics
Meta-analysis: Lactobacillus GG for treating acute gastroenteritis in children

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Medical disclaimer. This page is educational and does not replace advice from a qualified healthcare provider. Individual needs and risks vary — consult a professional before starting, stopping, or combining supplements, especially if you are pregnant or nursing, taking medication, or managing a health condition.