Form Comparison

Lactobacillus rhamnosus GG vs Saccharomyces boulardii

Q: What is the difference between Lactobacillus rhamnosus GG and Saccharomyces boulardii?

Neither is absorbed; both have moderate cost. Choose Lactobacillus rhamnosus GG when you want the best-studied single bacterial strain for antibiotic-associated diarrhea; choose Saccharomyces boulardii when you are taking antibiotics and want a probiotic they will not kill.

How Lactobacillus rhamnosus GG and Saccharomyces boulardii differ in how they work, evidence, tolerance, and cost.

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Quick verdict. Both have good evidence for preventing antibiotic-associated diarrhea, and the practical difference is that S. boulardii is a yeast, so antibiotics do not kill it and it can be taken at the same time. LGG is the best-studied bacterial strain, especially for antibiotic-associated and infectious diarrhea in children, but doses should be spaced away from antibiotics. Choose S. boulardii during antibiotics or as a C. difficile recurrence adjunct, unless you are critically ill or have a central line, where it carries a rare fungemia risk; choose LGG for children's diarrhea.

Side by Side

	Lactobacillus rhamnosus GG	Saccharomyces boulardii CNCM I-745
How it works	Survives stomach acid and bile and adheres to intestinal mucus; detectable in stool during use and for a short time after.	A yeast, so antibacterial drugs do not kill it; acts in the gut lumen and clears within days of stopping.
Typical dose	10-20 billion CFU daily	250-500 mg (5-10 billion CFU) daily
Common uses	antibiotic-associated diarrhea in children, acute infectious diarrhea in children	antibiotic-associated diarrhea, C. difficile recurrence (adjunct)
Side effects	Gas, bloating.	Rare fungemia in critically ill or catheterized patients.
Cost	Moderate	Moderate
Also called	LGG, Lacticaseibacillus rhamnosus GG, Culturelle	S. boulardii, Florastor

When to Choose Lactobacillus rhamnosus GG

Choose Lactobacillus rhamnosus GG when you want the best-studied single bacterial strain for antibiotic-associated diarrhea. In 2020 the genus was renamed Lacticaseibacillus; labels may use either name. Look for the GG strain designation.

Lactobacillus rhamnosus GG

The best-studied bacterial strain for antibiotic-associated diarrhea, especially in children.

What to look for: "GG" in the strain name and 10 billion CFU or more through expiration.

Find on iHerb Affiliate link

When to Choose Saccharomyces boulardii CNCM I-745

Choose Saccharomyces boulardii when you are taking antibiotics and want a probiotic they will not kill. Can be taken at the same time as antibiotics, unlike bacterial probiotics.

Saccharomyces boulardii CNCM I-745

The probiotic to take alongside antibiotics, because antibiotics cannot kill a yeast.

What to look for: Saccharomyces boulardii CNCM I-745 (Florastor or equivalent), 250-500 mg daily.

Find on iHerb Affiliate link

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References

NIH Office of Dietary Supplements. Probiotics: Fact Sheet for Health Professionals.

Gionchetti P, Rizzello F, Venturi A, et al. Oral bacteriotherapy as maintenance treatment in patients with chronic pouchitis: a double-blind, placebo-controlled trial. Gastroenterology. 2000;119(2):305-309.

Whorwell PJ, Altringer L, Morel J, et al. Efficacy of an encapsulated probiotic Bifidobacterium infantis 35624 in women with irritable bowel syndrome. Am J Gastroenterol. 2006;101(7):1581-1590.

Hill C, Guarner F, Reid G, et al. Expert consensus document: The International Scientific Association for Probiotics and Prebiotics consensus statement on the scope and appropriate use of the term probiotic. Nat Rev Gastroenterol Hepatol. 2014;11(8):506-514.

Szajewska H, Kołodziej M. Systematic review with meta-analysis: Saccharomyces boulardii in the prevention of antibiotic-associated diarrhoea. Aliment Pharmacol Ther. 2015;42(7):793-801.

Goldenberg JZ, Yap C, Lytvyn L, et al. Probiotics for the prevention of Clostridium difficile-associated diarrhea in adults and children. Cochrane Database Syst Rev. 2017;12(12):CD006095.

Suez J, Zmora N, Zilberman-Schapira G, et al. Post-antibiotic gut mucosal microbiome reconstitution is impaired by probiotics and improved by autologous FMT. Cell. 2018;174(6):1406-1423.

Ford AC, Harris LA, Lacy BE, Quigley EMM, Moayyedi P. Systematic review with meta-analysis: the efficacy of prebiotics, probiotics, synbiotics and antibiotics in irritable bowel syndrome. Aliment Pharmacol Ther. 2018;48(10):1044-1060.

Guo Q, Goldenberg JZ, Humphrey C, El Dib R, Johnston BC. Probiotics for the prevention of pediatric antibiotic-associated diarrhea. Cochrane Database Syst Rev. 2019;4(4):CD004827.

Su GL, Ko CW, Bercik P, et al. AGA clinical practice guidelines on the role of probiotics in the management of gastrointestinal disorders. Gastroenterology. 2020;159(2):697-705.