Home Ingredients Ibsium® (Saccharomyces cerevisiae CNCM I-3856)

Ibsium® (Saccharomyces cerevisiae CNCM I-3856)

Saccharomyces cerevisiae (strain CNCM I-3856)
Evidence Level
Limited
5 Clinical Trials
5 Documented Benefits
2/5 Evidence Score

Ibsium is a live probiotic yeast, Saccharomyces cerevisiae strain CNCM I-3856, sold by Gnosis by Lesaffre for digestive comfort; the same strain is marketed as Quatreflora for vaginal health. It is not the S. boulardii strain CNCM I-745. None of its three placebo-controlled trials in adults with IBS met its main outcome. In the first, more people on 500 mg a day reported less pain than on placebo, but this was not the main outcome and lost significance when all randomized people were counted.In 379 adults, 1,000 mg a day did not beat placebo, and in 456 adults with constipation the main pain score did not differ, although an added analysis found more people with at least a 30% drop in pain. An independent meta-analysis rated the pain benefit as low certainty. Lesaffre funded or staffed the main trials. As a live yeast, it is not for people with a central venous catheter or a weakened immune system.

Studied Dose 500 mg once daily for 8 weeks, or 1,000 mg daily as two 500 mg capsules for 8 to 12 weeks, in the bowel trials; one trial gave 8 billion CFU per 1,000 mg. A vaginal recovery study gave 500 or 1,000 mg (2.5 or 5 billion CFU) daily for 4 weeks.
Active Compound Live Saccharomyces cerevisiae strain CNCM I-3856, a proprietary Lesaffre strain registered in the French National Collection of Cultures of Microorganisms (CNCM) and identified by PCR interdelta typing and genome sequencing. Lesaffre writes the trade name as IbSium® and credits its development to Gnosis by Lesaffre; trade press describes the same strain as Quatreflora Biotic for vaginal use. Trial capsules were 500 mg hydroxypropyl methylcellulose capsules that, per the trial reports, contained only the yeast, at about 8 billion CFU per gram.

Benefits

Abdominal discomfort in adults with frequent bowel symptoms

In a first 8-week trial of 500 mg a day, 63% vs 47% of 179 adults with IBS analyzed were pain or discomfort responders (p = 0.04, though the printed 95% CI of 0.99 to 3.57 includes no effect). Independent reviewers noted this was not the main outcome, which was missed, and it was not significant when all 200 randomized were counted. A 12-week trial of 1,000 mg in 379 adults also missed its main outcome.

Supported by Trial 1

Abdominal pain and bloating with hard or infrequent stools

In 456 adults with IBS with constipation, 1,000 mg a day for 8 weeks did not change the main pain score versus placebo (p = 0.073); in an added analysis not among its prespecified endpoints, 45.1% vs 33.9% had at least a 30% drop in pain, and quality of life scored slightly higher. In a subgroup of the 379-person trial, the 180 people with constipation had less pain and bloating at 12 weeks.

Supported by Trial 3, Trial 2

Second-month bowel symptom scores in pooled trial data

A sponsor analysis pooling individual data from the first two trials (579 adults with IBS) found 12.3% lower abdominal pain and 9.2% lower bloating scores than placebo during the second month, but no difference at week 8 or over the full 8 weeks. Stools were softer in the constipation subgroup. Neither pooled trial met its main outcome, and the data came from Lesaffre.

Supported by Trial 1, Trial 2

Abdominal pain relief in independent pooled analyses of probiotic trials

An independent meta-analysis of 5 trials (1,482 adults with IBS) found fewer people with ongoing abdominal pain on this strain but rated the evidence low certainty, with very large differences between trials. A second found lower pain severity overall and with constipation, no effect on bloating, and included a trial where people also took standard IBS medicines.

Supported by Trial 1, Trial 2

Reaching the gut and the vaginal area after oral intake in healthy women

In 60 healthy women given 500 mg, 1,000 mg or placebo daily for 4 weeks, the strain was found in the stool of 90% of women taking it and in vaginal samples of 4 of 19 and 3 of 19. Vaginal Candida and lactobacilli did not differ between groups, and microbiome effects were small. Lesaffre funded and staffed the study.

Supported by Trial 5, Trial 3

Mechanism of action

1

Proposed fermentation and gut transit effects

Trial authors proposed that the yeast's sugar-splitting enzymes may help gut bacteria make short-chain fatty acids, which can speed small-bowel transit, and they cited a visceral pain-lowering effect in rodents. Transit was not measured in people, and stools were softer than on placebo only in constipation subgroups, not in the larger constipation trial.

2

Interference with E. coli toxins in simulated gut models (lab work)

In laboratory models of the human digestive tract, the strain did not change survival of an enterotoxigenic E. coli but lowered its toxin gene activity and toxin output, and 18 days of dosing raised Bifidobacterium, Lactobacillus and short-chain fatty acids in a simulated colon. These are lab results, not human outcomes.

3

Action against Candida in mice (vaginal application)

In mice, live I-3856 placed directly in the vagina sped clearance of Candida albicans, clumped with the fungus, cut its attachment to cells and lowered its shift to the invasive hyphal form. Oral intake was not tested, and these are animal results funded by Lesaffre.

Clinical trials

1
500 mg Daily vs Placebo in Adults With IBS: 8-Week RCT, Primary Outcome Not Met
PubMed

Randomized, double-blind, placebo-controlled trial; one 500 mg capsule of S. cerevisiae once daily for 8 weeks, then a 3-week washout, after a 2-week run-in; later papers identify the strain as CNCM I-3856. Two authors were from Lesaffre and one from Biofortis; no registry entry was found on ClinicalTrials.gov, and the full paper could not be read; a published comment by independent reviewers states the trial missed its primary outcome and that the responder analysis appears post hoc (Pineton de Chambrun et al. 2015, Dig Liver Dis)

Adults with IBS by Rome III criteria; 200 randomized (100 per arm) according to an independent comment and the sponsor's pooled analysis, with 179 analyzed (86 yeast, 93 placebo; 84% to 88% women).

Responders with improved abdominal pain or discomfort in the last 4 weeks: 63% vs 47% (54 of 86 vs 44 of 93; p = 0.04; odds ratio 1.88, printed 95% CI 0.99 to 3.57, which includes no effect). Independent reviewers report the primary outcome was not met and that, counting all 200 randomized and treating dropouts as nonresponders, the result was 54% vs 44% (p = 0.17). Bloating and bowel movement difficulty showed only nonsignificant trends, and stool frequency and consistency did not change. No constipation subgroup result is given in the abstract.

2
1,000 mg Daily in 379 Adults With IBS: 12-Week RCT, Primary Outcome Not Met
PubMed

Multicenter, randomized, double-blind, placebo-controlled trial (NCT01613456; the registry lists change in discomfort score at week 8 as the primary outcome, while the paper uses a responder outcome over the last 8 of 12 weeks); two 500 mg capsules (8 billion CFU per gram) or calcium phosphate and maltodextrin placebo daily for 12 weeks. Run within a French public research program; the writing was funded by Lesaffre, three authors were Lesaffre employees, three worked for Biofortis, which Lesaffre funded, and the lead author consulted for Lesaffre (Spiller et al. 2016, United European Gastroenterol J)

379 adults with IBS by Rome III criteria recruited by French general practitioners (192 yeast, 187 placebo); 180 had IBS with constipation.

The primary outcome, a 50% drop in weekly pain or discomfort for at least 4 of the last 8 weeks, did not differ (32.2% vs 26.9%, p > 0.05), and no symptom or quality of life score differed overall. In the constipation subgroup, pain or discomfort (p = 0.03) and bloating (p = 0.03) were lower at 12 weeks, but responder rates were 22.0% vs 21.4%. The abstract calls the subgroup analyses planned while the results section heads them post hoc. Of 16 adverse events judged possibly related, 14 were digestive, reported as 10 on yeast and 4 on placebo.

3
1,000 mg Daily in 456 Adults With IBS With Constipation: 8-Week RCT, Primary Outcome Not Met
PubMed

Multicenter, randomized, double-blind, placebo-controlled trial (NCT03150212); two 500 mg capsules giving 8 billion CFU, or maize starch placebo, daily for 8 weeks after a 2-week run-in. Product supplied by Gnosis by Lesaffre; six authors were Lesaffre employees, one a former employee, and two received Lesaffre research funding (Mourey et al. 2022, World J Gastroenterol)

456 adults with IBS with constipation by Rome IV criteria and baseline pain of 2 to under 6 on a 7-point scale (230 yeast, 226 placebo; 86% women).

The primary outcome, abdominal pain area under the curve over weeks 5 to 8, did not differ (difference -0.59, 95% CI -1.23 to 0.05, p = 0.073). In an added responder analysis not listed among the paper's prespecified secondary endpoints, 45.1% vs 33.9% had at least a 30% drop in pain (p = 0.017); the IBS quality of life score, a secondary objective, was 3.86 points higher (p = 0.047). Bloating fell by similar amounts in both groups, and stool frequency and form did not differ between groups. Adverse events per person did not differ; serious events were 1 on yeast and 2 on placebo.

4
Add-On to Standard IBS Treatment in 100 Adults: 8-Week RCT (drug co-treatment context)
PubMed

Prospective, randomized, placebo-controlled trial; S. cerevisiae CNCM I-3856 at 2 billion CFU twice daily or placebo for 8 weeks, added to standard IBS treatment; two of five authors were from Tablets India Limited; the abstract gives no blinding, registry or funding details (Gayathri et al. 2020, Int J Colorectal Dis)

100 newly diagnosed adults with IBS in India, grouped by IBS subtype before randomization.

Abdominal pain scores fell more on the yeast than on placebo (p < 0.001), and stool consistency improved more in the diarrhea subtype (p < 0.001), with similar changes reported in the other subtypes. No serious adverse events. Because everyone was also on standard IBS medicines, this is drug co-treatment in a diagnosed population; context only.

5
Oral I-3856 in 60 Healthy Women: 4-Week Vaginal Recovery RCT
PubMed

Exploratory, randomized, double-blind, placebo-controlled, three-arm trial (NCT03574844); 500 mg (2.5 billion CFU) or 1,000 mg (5 billion CFU) of the strain, or maize starch placebo, daily for 4 weeks. Lesaffre funded it, and all authors were Lesaffre employees; a second paper on the same trial analyzed vaginal microbiome sequencing (Decherf et al. 2020, Nutrients)

60 healthy women (20 per group); 57 completed. 52 women's samples were used in the microbiome paper.

The strain was found in vaginal samples of 4 of 19 women on 500 mg and 3 of 19 on 1,000 mg, and in stool of 90% of women taking it. Vaginal Candida albicans and lactobacilli did not differ between groups. In the microbiome paper, the yeast's effects were described as limited and were hard to separate from differences present at the start. No serious adverse events linked to the product or the research.

Side effects and drug interactions

Common Potential side effects

In the 456-person trial, adverse events per person did not differ from placebo over 8 weeks, and there was 1 serious adverse event on the yeast and 2 on placebo; the only one not ruled out as product-related (bowel obstruction) was on placebo.
In the 379-person trial, 16 adverse events were judged possibly related; 14 were digestive, reported as 10 on the yeast and 4 on placebo, including constipation (4 on yeast, 2 on placebo) and abdominal pain (2 on yeast); no serious event was linked to the product.
No serious adverse events linked to the product were reported in the vaginal recovery study, and none were recorded in the add-on trial. Published trials lasted 12 weeks or less.
Invasive Saccharomyces infections, mostly bloodstream infections, have been reported in people with intravascular catheters, on antibiotics, critically ill or immunosuppressed, and many cases followed S. boulardii probiotic use. People with a central venous catheter, a weakened immune system or a critical illness should not use live yeast probiotics.

Important Drug interactions

Antifungal medicines (for example fluconazole or nystatin) may kill the yeast and reduce its effect; the trials excluded people on recent antifungal treatment.
Antibiotics: as a yeast it is not the target of antibacterial antibiotics, but the trials excluded people on recent antibiotics, and antibiotic use is a common risk factor in reported yeast bloodstream infections. Ask your doctor before combining them.
Immunosuppressants and chemotherapy: use only with medical advice, because of the rare risk of yeast bloodstream infection in immunocompromised people.
IBS medicines: one trial added the yeast to standard IBS treatment, but no formal interaction study has been published.

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Frequently asked questions about Ibsium® (Saccharomyces cerevisiae CNCM I-3856)

What is Ibsium?

Ibsium (written IbSium® by its maker) is a branded live probiotic yeast, Saccharomyces cerevisiae strain CNCM I-3856, developed by Gnosis by Lesaffre and sold for digestive comfort. The same strain is marketed as Quatreflora for vaginal health. Its research applies to this strain only.

Does Ibsium help with abdominal pain and bloating?

The evidence is weak. None of the three placebo-controlled trials in adults with IBS (about 200, 379 and 456 people) met its main outcome. Some added analyses favored the yeast, such as more people with at least a 30% drop in pain in the largest trial, and an independent review rates the pain benefit as low certainty. See a doctor about ongoing abdominal symptoms.

How much Ibsium was used in studies?

Bowel trials used 500 mg once a day for 8 weeks, or 1,000 mg a day as two 500 mg capsules for 8 to 12 weeks, taken in the morning with breakfast or just before it. One trial gave 8 billion CFU per 1,000 mg. Follow the product label.

Is Ibsium the same as Saccharomyces boulardii?

No. Both are strains of the same yeast species, but Ibsium is CNCM I-3856 and the common S. boulardii probiotic is CNCM I-745. Probiotic effects are strain-specific, so results for one do not transfer to the other.

Is Ibsium safe?

In trials of up to 12 weeks, adverse events were mostly digestive and serious events were not more common than on placebo. Because it is a live yeast, people with a central venous catheter, a weakened immune system or a critical illness should not use it, as rare yeast bloodstream infections have been reported, mostly after S. boulardii use.

What is Ibsium used for?

NutraSmarts does not list Ibsium under a health category. What the research covers: In a first 8-week trial of 500 mg a day, 63% vs 47% of 179 adults with IBS analyzed were pain or discomfort responders (p = 0.04, though the printed 95% CI of 0.99 to 3.57 includes no effect).

Does Ibsium interact with any medications?

Possible interactions include: Antifungal medicines (for example fluconazole or nystatin) may kill the yeast and reduce its effect; the trials excluded people on recent antifungal treatment. If you take prescription medication, check with a pharmacist or doctor before using it.

How strong is the scientific evidence for Ibsium?

NutraSmarts rates the evidence for Ibsium as Limited (2 out of 5). It is backed by 5 study summaries and 17 cited references summarized on this page. A higher rating reflects more, larger, and better-designed human studies.

References(17 citations)

Evidence ratings on NutraSmarts are based on the totality of human clinical research, with emphasis on randomized controlled trials, meta-analyses, and systematic reviews. The references below directly support claims made throughout this page.

  1. Pineton de Chambrun G, Neut C, Chau A, Cazaubiel M, Pelerin F, Justen P, Desreumaux P. A randomized clinical trial of Saccharomyces cerevisiae versus placebo in the irritable bowel syndrome. Dig Liver Dis. 2015;47(2):119-24. doi: 10.1016/j.dld.2014.11.007.PubMedUsed to support: First randomized, double-blind, placebo-controlled trial in 179 adults with IBS (Rome III): 500 mg S. cerevisiae once daily for 8 weeks, then a 3-week washout. Responders with improved abdominal pain or discomfort in the last 4 weeks: 63% vs 47% (p = 0.04; OR 1.88, printed 95% CI 0.99 to 3.57). Other symptoms showed nonsignificant trends; stool frequency and consistency did not change. The abstract does not name the strain, but the later trial and the sponsor's pooled analysis identify it as CNCM I-3856. Two authors were from Lesaffre and one from Biofortis. Only the abstract was read. An independent published comment (Quinn and Ford 2015, PMID 25637452) states the trial missed its primary endpoint, that the abstract's responder result appears to be post hoc, and that with all 200 randomized patients counted (dropouts as nonresponders) it is 54% vs 44%, p = 0.17. The authors' reply (PMID 25747114) could not be read.
  2. Spiller R, Pélerin F, Cayzeele Decherf A, Maudet C, Housez B, Cazaubiel M, Jüsten P. Randomized double blind placebo-controlled trial of Saccharomyces cerevisiae CNCM I-3856 in irritable bowel syndrome: improvement in abdominal pain and bloating in those with predominant constipation. United European Gastroenterol J. 2016;4(3):353-62. doi: 10.1177/2050640615602571.PubMedUsed to support: Randomized, double-blind, placebo-controlled trial (NCT01613456) in 379 adults with IBS given 1,000 mg CNCM I-3856 (8 billion CFU per gram) or placebo daily for 12 weeks. The primary responder outcome did not differ (32.2% vs 26.9%), and no overall symptom, quality of life or relief measure differed. In the IBS with constipation subgroup (82 yeast, 98 placebo), pain or discomfort and bloating were lower at 12 weeks (p = 0.03 each) and total AUCs were lower, but responder rates did not differ (22.0% vs 21.4%). The abstract calls the subgroup analyses planned; the results section heads them post hoc. The writing was funded by Lesaffre; three authors were Lesaffre employees, three Biofortis employees (Biofortis received Lesaffre funding), and the lead author consulted for Lesaffre. PubMed lists an erratum (PMID 28344802).
  3. Mourey F, Decherf A, Jeanne JF, Clément-Ziza M, Grisoni ML, Machuron F, Legrain-Raspaud S, Bourreille A, Desreumaux P. Saccharomyces cerevisiae I-3856 in irritable bowel syndrome with predominant constipation. World J Gastroenterol. 2022;28(22):2509-2522. doi: 10.3748/wjg.v28.i22.2509.PubMedUsed to support: Randomized, double-blind, placebo-controlled trial (NCT03150212) in 456 adults with IBS with constipation (Rome IV) given 1,000 mg CNCM I-3856 (8 billion CFU) or placebo daily for 8 weeks. The primary outcome, abdominal pain AUC over weeks 5 to 8, did not differ (p = 0.073). Pain responders (at least 30% reduction) were 45.1% vs 33.9% (p = 0.017) and IBS quality of life was higher at week 8 (p = 0.047); bloating fell in both groups, and stool frequency and consistency did not differ between groups. Adverse events did not differ. The abstract leads with the responder result, which is not among the paper's listed prespecified secondary endpoints; the registry record (NCT03150212) lists only the pain AUC primary. Six authors were Lesaffre employees, one a former employee, and two received Lesaffre research funding; Gnosis by Lesaffre supplied the product.
  4. Cayzeele-Decherf A, Pélerin F, Leuillet S, Douillard B, Housez B, Cazaubiel M, Jacobson GK, Jüsten P, Desreumaux P. Saccharomyces cerevisiae CNCM I-3856 in irritable bowel syndrome: An individual subject meta-analysis. World J Gastroenterol. 2017;23(2):336-344. doi: 10.3748/wjg.v23.i2.336.PubMedUsed to support: Individual patient data meta-analysis by the sponsor of the two earlier trials (579 adults with IBS; data provided by the sponsor). Abdominal pain or discomfort was 12.3% lower than placebo in the second month (p = 0.0134) and bloating 9.2% lower (p = 0.0105), but not over the full 8 weeks or at week 8. A 1-point responder definition favored the yeast (OR 1.51, p = 0.024), while the 50% definition did not. Softer stools at week 8 (3.13 vs 2.58) were reported in the constipation subgroup; the abstract attributes them to the whole population. Authors were affiliated with Lesaffre; the paper reports no conflicts of interest.
  5. Gayathri R, Aruna T, Malar S, Shilpa B, Dhanasekar KR. Efficacy of Saccharomyces cerevisiae CNCM I-3856 as an add-on therapy for irritable bowel syndrome. Int J Colorectal Dis. 2020;35(1):139-145. doi: 10.1007/s00384-019-03462-4.PubMedUsed to support: Prospective, randomized, placebo-controlled trial in 100 newly diagnosed adults with IBS in India given S. cerevisiae CNCM I-3856 (2 billion CFU twice daily) or placebo for 8 weeks in addition to standard treatment. Abdominal pain fell more on the yeast (p < 0.001), and stool consistency improved more in the diarrhea subtype (p < 0.001). No serious adverse events. Two authors were from Tablets India Limited. Drug co-treatment in a diagnosed population; context only.
  6. Decherf A, Dehay E, Boyer M, Clément-Ziza M, Rodriguez B, Legrain-Raspaud S. Recovery of Saccharomyces cerevisiae CNCM I-3856 in Vaginal Samples of Healthy Women after Oral Administration. Nutrients. 2020;12(8):2211. doi: 10.3390/nu12082211.PubMedUsed to support: Exploratory randomized, double-blind, placebo-controlled trial (NCT03574844) in 60 healthy women given 500 mg (2.5 billion CFU) or 1,000 mg (5 billion CFU) CNCM I-3856 or placebo daily for 4 weeks; 57 completed. The strain was detected in vaginal samples of 4 of 19 and 3 of 19 women and in stool of 90% of those taking it. Vaginal C. albicans did not differ. No serious adverse events linked to the product or the research. All authors were Lesaffre employees, and Lesaffre funded the study.
  7. Oerlemans E, Ahannach S, Wittouck S, Dehay E, De Boeck I, Ballet N, Rodriguez B, Tuyaerts I, Lebeer S. Impacts of Menstruation, Community Type, and an Oral Yeast Probiotic on the Vaginal Microbiome. mSphere. 2022;7(5):e0023922. doi: 10.1128/msphere.00239-22.PubMedUsed to support: Vaginal microbiome sequencing of 52 healthy women from the same placebo-controlled trial (NCT03574844). Vaginal fungal loads stayed low after oral yeast. The probiotic group had higher Lactobacillus abundance and a trend toward lower Prevotella, but baseline differences complicated the analysis, and the authors called the yeast's impact limited. Three authors were Lesaffre employees, and Lesaffre funded a large part of the study.
  8. Goodoory VC, Khasawneh M, Black CJ, Quigley EMM, Moayyedi P, Ford AC. Efficacy of Probiotics in Irritable Bowel Syndrome: Systematic Review and Meta-analysis. Gastroenterology. 2023;165(5):1206-1218. doi: 10.1053/j.gastro.2023.07.018.PubMedUsed to support: Independent systematic review and meta-analysis of 82 randomized trials (10,332 adults with IBS) of probiotics versus placebo. For abdominal pain persisting after therapy, S. cerevisiae I-3856 in 5 trials (1,482 patients) gave a relative risk of 0.64 (95% CI 0.45 to 0.90) with very high heterogeneity (I2 93%), rated low certainty; continuous pain scores for Saccharomyces strains did not differ from placebo. PubMed lists a corrigendum (PMID 39207347). The risk of any adverse event was not significantly higher with probiotics.
  9. Maslennikov R, Gosteeva E, Ananeva V, Korshunova L, Kravtsowa A, Poluektova E, Ulyanin A, Sigidaev A, Kikhasurova P, Ivashkin V. Strain-Specific Systematic Review with Meta-Analysis of Probiotics Efficacy in the Treatment of Irritable Bowel Syndrome. J Clin Med. 2026;15(3):1152. doi: 10.3390/jcm15031152.PubMedUsed to support: Independent strain-specific meta-analysis of randomized placebo-controlled trials of single-strain probiotics in IBS. Four trials of S. cerevisiae CNCM I-3856 were included (one was the add-on trial with standard treatment); the strain reduced abdominal pain severity overall and in the constipation subgroups, but not in diarrhea-predominant or alternating subtypes; heterogeneity was high (I2 76.9%), more people reported pain reduction, there was no significant effect on bloating, and stool consistency improved in the constipation subgroup. It did not grade certainty. The authors declared no conflicts.
  10. Roussel C, De Paepe K, Galia W, de Bodt J, Chalancon S, Denis S, Leriche F, Vandekerkove P, Ballet N, Blanquet-Diot S, Van de Wiele T. Multi-targeted properties of the probiotic saccharomyces cerevisiae CNCM I-3856 against enterotoxigenic escherichia coli (ETEC) H10407 pathogenesis across human gut models. Gut Microbes. 2021;13(1):1953246. doi: 10.1080/19490976.2021.1953246.PubMedUsed to support: Laboratory study in dynamic models of the human digestive tract (TIM-1 and M-SHIME). CNCM I-3856 did not change survival of enterotoxigenic E. coli H10407 but repressed enterotoxin genes and lowered toxin production; 18 days of dosing raised Bifidobacterium, Lactobacillus and short-chain fatty acids in the simulated gut. Two authors were from Lesaffre. No human outcomes.
  11. Pericolini E, Gabrielli E, Ballet N, Sabbatini S, Roselletti E, Cayzeele Decherf A, Pélerin F, Luciano E, Perito S, Jüsten P, Vecchiarelli A. Therapeutic activity of a Saccharomyces cerevisiae-based probiotic and inactivated whole yeast on vaginal candidiasis. Virulence. 2017;8(1):74-90. doi: 10.1080/21505594.2016.1213937.PubMedUsed to support: Mouse study: live S. cerevisiae CNCM I-3856 given intravaginally after Candida albicans challenge sped fungal clearance, caused coaggregation, reduced adherence to epithelial cells and suppressed hyphal switching and aspartyl protease expression. Vaginal application in animals, not oral use in people. Funded through a service agreement with Lesaffre International; four authors were Lesaffre staff.
  12. Enache-Angoulvant A, Hennequin C. Invasive Saccharomyces infection: a comprehensive review. Clin Infect Dis. 2005;41(11):1559-68. doi: 10.1086/497832.PubMedUsed to support: Review of 92 published cases of invasive Saccharomyces infection through May 2005. Blood was the most frequent site, intravascular catheters and antibiotic therapy were the most frequent predisposing factors, and S. boulardii accounted for 51.3% of fungemias. The authors advised special caution with S. boulardii probiotic preparations. Not specific to CNCM I-3856.
  13. Vinayagamoorthy K, Pentapati KC, Prakash H. Epidemiology of Saccharomyces fungemia: A systematic review. Med Mycol. 2023;61(2):myad014. doi: 10.1093/mmy/myad014.PubMedUsed to support: Systematic review of 108 analyzed cases of Saccharomyces fungemia reported from 2005 to 2022: 67.6% had received S. boulardii probiotics, with intensive care stay, parenteral or enteral feeding, diarrhea and diabetes as linked risk factors, and immunosuppression among those without probiotics. All-cause mortality was 36.1%. Not specific to CNCM I-3856.
  14. Lesaffre International. A Randomized, Double-blind, Placebo Controlled Study to Evaluate the Effect of Saccharomyces Cerevisiae on Improving the Effectiveness of Conventional Treatment of Vulvo-vaginal Candidiasis (NCT02345096) ClinicalTrials.gov registry record. 2026;Registry record, accessed 2026..SourceUsed to support: Not PubMed-indexed (trial registry record, read in 2026). Lesaffre-sponsored placebo-controlled trial of one oral capsule of S. cerevisiae CNCM I-3856 a day added to conventional treatment of vulvovaginal candidiasis, with vaginal Candida albicans counts as the primary outcome. It was terminated for recruitment difficulties after 22 participants, and no results are posted. A diagnosed population on antifungal co-treatment.
  15. Lesaffre. Improving intestinal and digestive comfort Lesaffre company website. 2021;Company page dated March 4, 2021; accessed 2026..SourceUsed to support: Not PubMed-indexed (company page, read in 2026). Names IbSium® as a patented, proprietary probiotic yeast (S. cerevisiae CNCM I-3856) developed by Gnosis by Lesaffre, states it needs no refrigeration and has a three-year shelf life, and makes marketing claims about digestive comfort. It gives no dose. A product description, not health evidence.
  16. Nutrition Insight. Yeast-based probiotics: Gnosis by Lesaffre sheds light on Quatreflora mechanisms Nutrition Insight (trade press). 2020;Published May 20, 2020; accessed 2026..SourceUsed to support: Not PubMed-indexed (trade press, read in 2026). Describes the S. cerevisiae CNCM I-3856 strain, called Quatreflora Biotic, from Gnosis by Lesaffre, as studied for vaginal infections, with the mouse work using intravaginal administration. It gives no human dose.
  17. Quinn JA, Ford AC. Comment on "A randomized clinical trial of Saccharomyces cerevisiae versus placebo in the irritable bowel syndrome" by Guillaume Pineton de Chambrun et al. [Digestive and Liver Disease 2015;47:119-24]. Dig Liver Dis. 2015;47(5):437. doi: 10.1016/j.dld.2015.01.002.PubMedUsed to support: Letter by independent IBS meta-analysts on the first 500 mg trial: the trial failed to show a significant difference in its primary endpoint and almost all secondary endpoints; the abstract's responder result (54 of 86 vs 44 of 93, p = 0.04) appears to be post hoc and was not a strict intention-to-treat analysis; with all 200 randomized patients counted and dropouts treated as nonresponders, response was 54 of 100 vs 44 of 100 (p = 0.17). Read as the accepted manuscript on White Rose Research Online. The authors declared no conflicts.