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Saccharomyces boulardii is a tropical species of yeast first isolated from lychee and mangosteen fruit in 1923 by French scientist Henri Boulard. S. boulardii (synonym: S. cervisiae var boulardii and Saccharomyces cerevisiae Hansen CBS 5926) is a yeast that could be assigned to the subtype of S. cerevisiae species. It is related to, but distinct from, Saccharomyces cerevisiae in several taxonomic, metabolic, and genetic properties. S. boulardii is sometimes used as a probiotic with the purpose of introducing beneficial active cultures into the large and small intestine, as well as conferring protection against pathogenic microorganisms in the host. However, in immunocompromised individuals, S. boulardii has been associated with fungemia or localized infection, which may be fatal. Overall, S. boulardii is safe for use in otherwise healthy populations and fungemia with S. boulardii has not been reported, to the best of the recent evidences in immunocompetent patients. In HIV-1-infected patients the therapy with Sb resulted to be safe. Boulard first isolated this yeast after he observed natives of Southeast Asia chewing on the skin of lychee and mangosteen in an attempt to control the symptoms of cholera. In healthy patients, S. boulardii has been shown to be nonpathogenic and nonsystemic (it remains in the gastrointestinal tract rather than spreading elsewhere in the body). It grows at 37 °C (98.6 °F). In addition, the popular genome editing tool CRISPR-Cas9 was proven to be effective in S. boulardii.
- 1 Medical uses
- 2 Mechanisms of action
- 3 References
Irritable bowel syndrome
A prospective placebo-controlled study found patients with diarrhea-predominant irritable bowel syndrome had a significant reduction on the number and consistency of bowel movements.
Another study in 2011 did not find any change in bowel frequency.
Inflammatory bowel disease
Further benefits to inflammatory bowel disease patients have been suggested in the prevention of relapse in Crohn's disease patients currently in remission and benefits to ulcerative colitis patients currently presenting with moderate symptoms.
Austrian vacationers taking S. boulardii traveling around the world were found to have significantly fewer occurrences of travelers' diarrhea than those taking placebo. A meta-analysis of 12 studies from 1977 to 2005 investigating the efficacy of probiotics found them to be safe and effective for the treatment of travelers' diarrhea, having a pooled relative risk of 0.85 with respect to placebo (between 0.79 and 0.91 with 95% confidence). Three of four studies concerning S. boulardii found it to be an effective treatment. 
Evidence exists for its use in the preventative treatment of antibiotic-associated diarrhea (AAD) in adults. Further evidence indicates its use to prevent AAD in children. The potential efficacy of probiotic AAD prevention is dependent on the probiotic strain(s) used and on the dosage. A Cochrane Collaboration systematic review, in which 16 randomized clinical trials (n=3432 participants) were analyzed, concluded that treatments with less than 5000 million CFUs/day did not show a significant decrease of AAD. However, patients treated with ≥5000 million CFUs/day (including L. rhamnosus and Saccharomyces boulardii) had 60% lower relative risk (95%CI: 44–71%) of experiencing AAD than untreated patients.[needs update]
S. boulardii has been shown to significantly increase the recovery rate of stage IV AIDS patients suffering from diarrhea versus placebo. On average, patients receiving S. boulardii gained weight, while the placebo group lost weight over the 18-month trial. No adverse reactions were observed in these immunocompromised patients.
Elimination of Helicobacter pylori infection
The addition of S. boulardii to the standard triple medication protocol for elimination of Helicobacter pylori infection showed a significant increase in eradication rates in a meta-analysis, though eradication rates were still not exceptional. The supplement also significantly decreased usual side effects of H. pylori eradication therapy including diarrhea and nausea.
Mechanisms of action
S. boulardii secretes a 54-kDa protease, in vivo, which has been shown to degrade toxins A and B, secreted from C. difficile, and inhibit their binding to receptors along the brush border. This leads to a reduction in the enterotoxinic and cytotoxic effects of C. difficile infection.
Escherichia coli and Salmonella typhimurium, two pathogenic bacteria often associated with acute infectious diarrhea, were shown to strongly adhere to mannose on the surface of S. boulardii via lectin receptors (adhesins). Once the invading microbe is bound to S. boulardii, it is prevented from attaching to the brush border; it is then eliminated from the body during the next bowel movement.
Trophic effects on enterocytes
The hypersecretion of water and electrolytes (including chloride ions), caused by cholera toxin during a Vibrio cholerae infection, can be reduced significantly with the introduction of S. boulardii. A 120-kDa protease secreted by S. boulardii has been observed to have an effect on enterocytes lining the large and small intestinal tract–inhibiting the stimulation of adenylate cyclase, which led to the reduction in enterocytic cyclic adenosine monophosphate (cAMP) production and chloride secretion.
During an E. coli infection, myosin light chain is phosphorylated leading to the degradation of the tight junctions between intestinal mucosa enterocytes. S. boulardii has been shown to prevent this phosphorylation, leading to a reduction in mucosal permeability, and thus a decrease in the translocation of the pathogenic bacteria.
Polyamines (spermidine and spermine) have been observed to be released from S. boulardii in the rat ileum. Polyamines have been theorized to stimulate the maturation and turnover of small intestine enterocytes.
Interleukin 8 (IL-8) is a proinflammatory cytokine secreted during an E. coli infection in the gut. S. boulardii has been shown to decrease the secretion of IL-8 during an E. coli infection; S. boulardii could have a protective effect in inflammatory bowel disease. S. boulardii may exhibit part of its anti-inflammatory potential through modulation of dendritic cell phenotype, function, and migration by inhibition of their immune response to bacterial microbial surrogate antigens such as lipopolysaccharide. A recent study showed that culture of primary human myeloid dendritic cells CD1c+CD11c+CD123- DC (mDC) in the presence of S. boulardii culture supernatant (active component molecular weight < 3 kDa as evaluated by membrane partition chromatography) significantly reduced expression of the co-stimulatory molecules CD40 and CD80 and the dendritic cell mobilization marker CC-chemokine receptor CCR7 (CD197) induced by the prototypical microbial antigen lipopolysaccharide. Moreover, secretion key proinflammatory cytokines like TNF-α and IL-6 were notably reduced, while the secretion of anti-inflammatory IL-10 did increase. Finally, S. boulardii supernatant inhibited the proliferation of naïve T-cells in a mixed lymphocyte reaction with mDC.
Increased levels of disaccharidases
The trophic effect on enterocytes has been shown to increase levels of disaccharidases such as lactase, sucrase, maltase, glucoamylase, and N-aminopeptidase in the intestinal mucosa of humans and rats. This can lead to the increased breakdown of disaccharides into monosaccharides that can then be absorbed into the bloodstream via enterocytes. This can help in the treatment of diarrhea, as the level of enzymatic activity has diminished and carbohydrate cannot be degraded and absorbed.
Increased immune response
- Rajkowska K, Kunicka-Styczyńska A. Phenotypic and Genotypic Characterization of Probiotic Yeasts. Biotechnology & Biotechnological Equipment. 2009;23(Suppl 1):662-665
- Łukaszewicz M. Saccharomyces cerevisiae var. boulardii – Probiotic Yeast. Chapter 16. Saccharomyces cerevisiae var. boulardii – Probiotic Yeast. Immunology and Microbiology » "Probiotics", book edited by Everlon Cid Rigobelo, ISBN 978-953-51-0776-7, Published: October 3, 2012
- Malgoire JY; Bertout S; Renaud F; Bastide JM; Mallié M (2005). "Typing of Saccharomyces cerevisiae clinical strains by using microsatellite sequence polymorphism". J. Clin. Microbiol. 43 (3): 1133–7. doi:10.1128/JCM.43.3.1133-1137.2005. PMC . PMID 15750073.
- Rajkowska, Katarzyna; et al. (April 2012). "Probiotic Activity of Saccharomyces cerevisiae var. boulardii Against Human Pathogens" (PDF). Food Technology and Biotechnology. 50: 230–236. Retrieved 18 January 2014.
- Toma, Malda Maija; et al. (June 2005). "Effect of Probiotic Yeast on Genotoxicity" (PDF). Food Technology and Biotechnology. 43: 301–305. Retrieved 18 January 2014.
- Soccol, Carlos Ricardo; et al. (June 2010). "The Potential of Probiotics: A Review" (PDF). Food Technology and Biotechnology. 48: 413–434. Retrieved 18 January 2014.
- Santino I; Alari A; Bono S; Teti E; Marangi M; Bernardini A; Magrini L; Di Somma S; Teggi A (2014). "Saccharomyces cerevisiae fungemia, a possible consequence of the treatment of Clostridium difficile colitis with a probioticum". Int J Immunopathol Pharmacol. 27 (1): 143–6. PMID 24674691.
- Kelesidis T, Pothoulakis C. Ther Adv Gastroenterol. 2012;5(2):111–125
- Canani RB, Cucchiara S, Cuomo R, Pace F, Papale F. Saccharomyces boulardii: a summary of the evidence for gastroenterology clinical practice in adults and children. European Review for Medical and Pharmacological Sciences. 2011;15:809-822
- McFarland L; Bernasconi P (1993). "Saccharomyces boulardii: a review of an innovative biotherapeutic agent". Microb Ecol Health Dis. 6 (4): 157–71. doi:10.3109/08910609309141323.
- Liu, Jing-Jing (2016). "Metabolic Engineering of Probiotic Saccharomyces boulardii". Appl Environ Microbiol. 82 (8): 2280–7. doi:10.1128/AEM.00057-16. PMC . PMID 26850302.
- Vandenplas Y (July 1999). "Bacteria and yeasts in the treatment of acute and chronic infectious diarrhea. Part II: Yeasts". Clin. Microbiol. Infect. 5 (7): 389–395. doi:10.1111/j.1469-0691.1999.tb00162.x. PMID 11853563.
- Maupas J; Champemont P; Delforge M (1983). "Treatment of irritable bowel syndrome with Saccharomyces boulardii: a double blind, placebo controlled study". Medicine Chirurgie Digestives. 12 (1): 77–9.
- Choi CH; Jo SY; Park HJ; Chang SK; Byeon JS; Myung SJ (2011). "A randomized, double-blind, placebo-controlled multicenter trial of saccharomyces boulardii in irritable bowel syndrome: effect on quality of life". J. Clin. Gastroenterol. 45: 679–83. doi:10.1097/MCG.0b013e318204593e. PMID 21301358.
- Guslandi M; Mezzi G; Sorghi M; Testoni PA (2000). "Saccharomyces boulardii in maintenance treatment of Crohn's disease". Dig. Dis. Sci. 45 (7): 1462–4. doi:10.1023/A:1005588911207. PMID 10961730.
- Guslandi M; Giollo P; Testoni PA (2003). "A pilot trial of Saccharomyces boulardii in ulcerative colitis". European Journal of Gastroenterology & Hepatology. 15 (6): 697–8. doi:10.1097/01.meg.0000059138.68845.06. PMID 12840682.
- Kollaritsch H; Kemsner P; Wiedermann G; Scheiner O (1989). "Prevention of traveler's diarrhoea. Comparison of different non-antibiotic preparations". Travel Med Int: 9–17.
- McFarland LV (2007). "Meta-analysis of probiotics for the prevention of traveler's diarrhea". Travel Med Infect Dis. 5 (2): 97–105. doi:10.1016/j.tmaid.2005.10.003. PMID 17298915.
- McFarland LV, Surawicz CM, Greenberg RN, et al. (1995). "Prevention of beta-lactam-associated diarrhea by Saccharomyces boulardii compared with placebo". Am. J. Gastroenterol. 90 (3): 439–48. PMID 7872284.
- Kotowska M; Albrecht P; Szajewska H (2005). "Saccharomyces boulardii in the prevention of antibiotic-associated diarrhoea in children: a randomized double-blind placebo-controlled trial". Aliment. Pharmacol. Ther. 21 (5): 583–90. doi:10.1111/j.1365-2036.2005.02356.x. PMID 15740542.
- Doron SI, Hibberd PL, Gorbach SL; Hibberd; Gorbach (July 2008). "Probiotics for prevention of antibiotic-associated diarrhea". J Clin Gastroenterol. 42 (Suppl 2): S58–63. doi:10.1097/MCG.0b013e3181618ab7. PMID 18542041.
- Surawicz CM (July 2008). "Role of probiotics in antibiotic-associated diarrhea, Clostridium difficile-associated diarrhea, and recurrent Clostridium difficile-associated diarrhea". J Clin Gastroenterol. 42 (Suppl 2): S64–70. doi:10.1097/MCG.0b013e3181646d09. PMID 18545161.
- Johnston BC, Goldenberg JZ, Vandvik PO, Sun X, Guyatt GH; Goldenberg; Vandvik; Sun; Guyatt (2011). "Probiotics for the prevention of pediatric antibiotic-associated diarrhea". Cochrane Database Syst Rev (11): CD004827. doi:10.1002/14651858.CD004827.pub3. PMID 22071814.
- Saint-Marc T; Blehaut H; Musial C; Touraine J (1995). "AIDS related diarrhea: a double-blind trial of Saccharomyces boulardii". Sem Hôsp Paris. 71: 735–41.
- Szajewska H; Horvath A; Kołodziej M (2015). "Systematic review with meta-analysis: Saccharomyces boulardii supplementation and eradication of Helicobacter pylori infection". Alimentary Pharmacology & Therapeutics. 41 (12): 1237–1245. doi:10.1111/apt.13214.
- Roberts, Tamalee; Stark, Damien; Harkness, John; Ellis, John (2014-05-28). "Update on the pathogenic potential and treatment options for Blastocystis sp". Gut Pathogens. 6: 17. doi:10.1186/1757-4749-6-17. ISSN 1757-4749. PMC . PMID 24883113.
- Dinleyici, Ener Cagri; Eren, Makbule; Dogan, Nihal; Reyhanioglu, Serap; Yargic, Zeynel Abidin; Vandenplas, Yvan (2011-03-01). "Clinical efficacy of Saccharomyces boulardii or metronidazole in symptomatic children with Blastocystis hominis infection". Parasitology Research. 108 (3): 541–545. doi:10.1007/s00436-010-2095-4. ISSN 1432-1955. PMID 20922415.
- Castagliuolo I; Riegler MF; Valenick L; LaMont JT; Pothoulakis C (1999). "Saccharomyces boulardii protease inhibits the effects of Clostridium difficile toxins A and B in human colonic mucosa". Infect. Immun. 67 (1): 302–7. PMC . PMID 9864230.
- Gedek BR (1999). "Adherence of Escherichia coli serogroup O 157 and the Salmonella typhimurium mutant DT 104 to the surface of Saccharomyces boulardii". Mycoses. 42 (4): 261–4. doi:10.1046/j.1439-0507.1999.00449.x. PMID 10424093.
- Czerucka D; Rampal P (1999). "Effect of Saccharomyces boulardii on cAMP- and Ca2+ -dependent Cl- secretion in T84 cells". Dig. Dis. Sci. 44 (11): 2359–68. doi:10.1023/A:1026689628136. PMID 10573387.
- Dahan S; Dalmasso G; Imbert V; Peyron JF; Rampal P; Czerucka D (2003). "Saccharomyces boulardii interferes with enterohemorrhagic Escherichia coli-induced signaling pathways in T84 cells". Infect. Immun. 71 (2): 766–73. doi:10.1128/IAI.71.2.766-773.2003. PMC . PMID 12540556.
- Buts JP; De Keyser N; De Raedemaeker L (1994). "Saccharomyces boulardii enhances rat intestinal enzyme expression by endoluminal release of polyamines". Pediatr. Res. 36 (4): 522–7. doi:10.1203/00006450-199410000-00019. PMID 7816529.
- Thomas S; Przesdzing I; Metzke D; Schmitz J; Radbruch A; Baumgart DC (2009). "Saccharomyces boulardii inhibits lipopolysaccharide-induced activation of human dendritic cells and T cell proliferation". Clin Exp Immunol. 156 (1): 78–87. doi:10.1111/j.1365-2249.2009.03878.x. PMC . PMID 19161443.
- Buts JP; Bernasconi P; Van Craynest MP; Maldague P; De Meyer R (1986). "Response of human and rat small intestinal mucosa to oral administration of Saccharomyces boulardii". Pediatr. Res. 20 (2): 192–6. doi:10.1203/00006450-198602000-00020. PMID 3080730.
- Zaouche A, Loukil C, De Lagausie P, et al. (2000). "Effects of oral Saccharomyces boulardii on bacterial overgrowth, translocation, and intestinal adaptation after small-bowel resection in rats". Scand. J. Gastroenterol. 35 (2): 160–5. doi:10.1080/003655200750024326. PMID 10720113.
- Buts JP; Bernasconi P; Vaerman JP; Dive C (1990). "Stimulation of secretory IgA and secretory component of immunoglobulins in small intestine of rats treated with Saccharomyces boulardii". Dig. Dis. Sci. 35 (2): 251–6. doi:10.1007/BF01536771. PMID 2302983.