Naturally Immune For Life

Saccharomyces boulardii CNCM I-745, marketed widely under the brand name Florastor, is one of the most researched probiotic yeasts in the world. Unlike typical probiotic bacteria, Saccharomyces boulardii is a non-pathogenic yeast with unique properties that make it effective for supporting digestive health. Its history, function, and how it compares to other forms of S. boulardii offer important insights for anyone seeking reliable probiotic options.

History of Development

The discovery of Saccharomyces boulardii dates back to 1923 when French microbiologist Henri Boulard traveled to Southeast Asia during a cholera outbreak. He observed that locals consuming tea made from lychee and mangosteen peels experienced fewer digestive symptoms. Upon investigation, Boulard isolated a yeast strain from the fruit skins, naming it Saccharomyces boulardii in his own honor. Decades later, the specific strain CNCM I-745 was registered in the French National Collection of Microorganism Cultures (CNCM) to ensure genetic stability and reproducibility (PubMed ID: 22186627).

Florastor became the commercial name for this strain and remains a leader in probiotic yeast supplementation today. Its key benefits include supporting gut flora balance, preventing antibiotic-associated diarrhea, and reducing symptoms of gastrointestinal disorders such as irritable bowel syndrome (IBS) and inflammatory bowel disease (IBD).

Does Every Form of Saccharomyces boulardii Work the Same?

While S. boulardii is the species name, not all products are identical. Research consistently emphasizes that strain specificity matters. The CNCM I-745 strain used in Florastor has been extensively studied in clinical trials, showing consistent efficacy for preventing antibiotic-associated diarrhea, treating Clostridium difficile infections, and reducing the duration of acute diarrhea in children and adults (PubMed ID: 29360848).

Generic or off-brand S. boulardii supplements may claim to offer the same benefits, but unless they specifically identify CNCM I-745 and prove genetic stability, their effectiveness could vary. Differences in cultivation methods, storage conditions, and even packaging can impact the viability and performance of probiotic yeast products.

How Saccharomyces boulardii Works

Unlike bacteria-based probiotics, S. boulardii is naturally resistant to antibiotics, making it ideal during or after antibiotic treatment. It works by several mechanisms:

• Inhibiting the binding of pathogens to intestinal walls

• Neutralizing bacterial toxins

• Modulating immune responses to reduce inflammation

• Promoting the production of secretory IgA, a key immune system antibody

These actions help restore gut homeostasis, prevent pathogen overgrowth, and support intestinal barrier function.

Conclusion

Florastor’s Saccharomyces boulardii CNCM I-745 represents a gold standard in probiotic yeast therapy, backed by decades of research. While other forms of S. boulardii exist, not all are created equally. Consumers should prioritize clinically studied strains to ensure the best results. As the understanding of gut health deepens, choosing probiotic products based on strain specificity and scientific evidence becomes increasingly important for optimal digestive and immune support.