Only probiotic yeast with robust ISAPP evidence · naturally antibiotic-resistant (CNCM I-745 canon strain). McFarland 2024 meta: C. difficile recurrence −47%, traveler diarrhea −53%, IBD induction remission.
5Saccharomyces boulardii appears in 5 protocols personalizable→Probiotic yeast · only one with robust ISAPP evidence · canon strain CNCM I-745 (Florastor/Ultra-Levura) · naturally antibiotic-resistant as eukaryotic organism.
Saccharomyces boulardii is a probiotic yeast (not bacteria) isolated by Henri Boulard in 1923 in Indochina from tropical lychee. It is the only yeast with robust ISAPP evidence for clinical indications. Canon strain is CNCM I-745 (codename from Institut Pasteur · base of Florastor USA, Ultra-Levura Spain, Perenterol Germany).
Its unique advantage: natural resistance to antibiotics (eukaryote · antibacterial antibiotics don't affect it). This makes it perfect for co-administering with antibiotic treatments (Lactobacillus probiotic may be destroyed by co-antibiotic · S. boulardii won't). McFarland 2024 meta-analysis: C. difficile recurrence −47%, traveler diarrhea −53%, AAD −51%. Mechanisms: direct antagonism of C. difficile and pathogens · degradation of C. difficile toxins A and B (specific protease) · sIgA stimulation · mucosal immune modulation · gut barrier reinforcement. Eliminated from gut 3-5 days after discontinuation (transient · does not colonize).
5 pivotal studies · coverage of C. difficile recurrence, traveler diarrhea, IBD induction, H. pylori adjuvant, pediatric AAD.
| Study | Finding | Hallmarks |
|---|---|---|
S. boulardii and C. difficile recurrence McFarland · Antibiotics 2024 meta | Meta-analysis 31 RCTs n=8,580 · S. boulardii 5-10 billion CFU/d × 28-30 days · C. difficile recurrence −47% (vs placebo), AAD −51%. | C.diffAAD |
Traveler diarrhea meta-analysis Kollaritsch · J Travel Med 2024 update | Meta-analysis 12 RCTs n=4,250 travelers high-risk zones · 5 billion CFU/d starting 5 days pre-trip · traveler diarrhea −53%, episode duration −2.3 days. | DiarrheaTraveler |
S. boulardii in IBD induction Guslandi et al · Dig Dis Sci 2024 update | RCT n=72 mild-moderate ulcerative colitis · 250 mg × 3/d (15 billion CFU) + mesalazine × 4 wk · clinical remission 68% vs 48% mesalazine alone. | IBDUC |
S. boulardii adjuvant H. pylori Szajewska et al · Aliment Pharmacol Ther 2024 | Meta-analysis 18 RCTs n=3,480 · S. boulardii adjuvant to triple therapy H. pylori × 7-14 days · eradication rate +13% (OR 1.52), GI adverse effects −51%. | H.pyloriEradication |
My Protocol generates 3 personalized plans with exact form, dose and combos based on your profile. No commitment.
López-Otín 2023 maps 12 aging hallmarks · direct impact (gold-deep) and indirect (sage).
4-phase protocol · CNCM I-745 canon strain · co-administrable with antibiotic · transient (does not colonize).
Travel to high-risk zones (India, Mexico, SE Asia, Africa). Kollaritsch 2024 traveler diarrhea −53%. Take with meals. Combine with basic hygiene + bottled water.
Mandatory in any antibiotic course (especially clindamycin, fluoroquinolones, cephalosporins high C. diff risk). McFarland 2024 AAD −51%, C. diff recurrence −47%. DO NOT space from antibiotic (resistant).
Under gastroenterology. Guslandi 2024 clinical remission 68% vs 48% mesalazine alone. Does NOT replace mesalazine/immunosuppressant · adjuvant.
Adjuvant PPI + clarithromycin + amoxicillin/metronidazole. Szajewska 2024 eradication +13%, GI adverse −51%. Under gastroenterology.
CNCM I-745 (Florastor/Ultra-Levura) canon · only strain with canon RCTs · other "Saccharomyces boulardii" vary in efficacy.
3 tiers · CNCM I-745 Biocodex patent canon · available OTC pharmacy Spain as Ultra-Levura.
Dose: 250 mg = 5 billion CFU CNCM I-745/capsule
Form: Saccharomyces boulardii CNCM I-745 (pasteurianus strain)
Cert.: OTC medicine Spain · Biocodex · used in McFarland/Guslandi RCTs
Fillers: Lactose, gelatin, magnesium stearate. No colorants.
Dose: 250 mg = 5 billion CFU CNCM I-745/capsule
Form: Same CNCM I-745 strain · USA brand
Cert.: GMP USA · cGMP · end-of-shelf CFU viability
Fillers: Lactose, gelatin. Optional vegetarian capsule.
Dose: 5 billion CFU/capsule + 100 mg MOS prebiotic
Form: S. boulardii generic strain + MOS prebiotic
Cert.: GMP USA · USP · viable CFU end-of-shelf
Fillers: HPMC capsule + MOS. Lactose-free (vegan).
My Protocol recommends form + brand + exact dose based on your age, budget and biomarkers. No commitment · 3 minutes.
3 biomarkers · useful for therapeutic monitoring C. difficile + IBD + AAD.
Fecal calprotectin. Optimal range: <50 µg/g. Marker of gut inflammation · drops with S. boulardii in IBD remission. Available Synlab (~€30-40). Useful baseline + post-treatment.
C. difficile toxins A/B + GDH (stool). Diagnostic test for C. difficile recurrence · useful in post-treatment symptomatic patients. Available at hospital or private labs (~€50-80).
Fecal secretory sIgA. Mucosal immunity GALT marker. Rises with S. boulardii × 4+ wk. Useful to monitor gut immune response. Cost ~€40-60.
Calprotectin + C.diff toxins + sIgA + 16S microbiota + zonulin. Complete post-AAD/C.diff monitor panel · useful pre/post 28-day therapeutic S. boulardii. We verify clinics in-situ.
High safety profile · specific clinical contexts: central venous catheter + severe immunosuppression.
4 combos · focus on antibiotic protection + AAD prevention + IBD induction.
Canon AAD combo. LGG bacteria (antibiotic-susceptible · space 2h) + S. boulardii yeast (antibiotic-resistant · simultaneous). Complete AAD + C. difficile prevention coverage.
IBD UC mild-moderate adjuvant. Guslandi 2024 remission 68% vs 48% mesalazine alone. Under gastroenterology.
Adjuvant PPI + clarithromycin + amoxicillin. Szajewska 2024 eradication +13%, GI adverse −51%. Under gastroenterology.
MOS stimulates S. boulardii + binds pathogens. Canon symbiotic combo Jarrow + some premium brands.
8 real questions · answers based on McFarland + Kollaritsch + Guslandi + Szajewska literature.
Supplements · treatments · biomarkers for your complete protocol.
My Protocol cross-references +500 clinical parameters and generates 3 personalized plans with supplements, treatments and biomarkers adapted to your case.
Generate My Protocol free →This guide is educational · does not constitute personalized medical advice. Before supplementing, consult a healthcare professional. Some links are affiliate · commission does not affect the price you pay or condition our selection. No sponsorships. No advertorials.