What is Saccharomyces boulardii?

Simply stated, Saccharomyces boulardii (S. boulardii) is a strain of yeast that was isolated from the superfoods, mangosteen and lychee fruit, in 1923 by the French scientist, Henri Boulard (hence the name). Since it is a yeast, it is also a kind of fungus.

Now, a few words on what it is not. S. boulardii is NOT the exact same strain as Saccharomyces cerevisiae, which is commonly called baker’s and brewer’s yeast, nor is it Saccharomyces exiguous, which is the wild yeast found naturally in vegetables, fruits and grains and is the source of sourdough starters.

To safely make it into a probiotic, S. boulardii is typically freeze-dried to keep it chemically stable. This process is known as lyophilization or lyo (for short). Thus, probiotics are often labeled “Saccharomyces boulardii lyo”.

To review, probiotics are beneficial substances, such as bacteria, yeast or fungus, which help improve the health and function of your intestinal tract.

What can this fungus fix?


Can a fungus fix your face? According to German researchers, it can. A preliminary study found more than 80% of those taking S. boulardii experienced complete or considerable healing of acne in 5 months.1


Studies have shown S. boulardii is an effective remedy for acute diarrhea in children and adults.2 This is the short-term diarrhea that typically lasts for no more than two weeks. An analysis of 12 studies showed that taking just one 500 mg dose of S. boulardii each day while traveling significantly reduces the risk of traveler’s diarrhea.3 One of the biggest advantages of this probiotic over others is that S. boulardii can be easily tossed into your luggage, as it does not need to be refrigerated. Researchers now believe that S. boulardii actually helps to promote recovery from diarrhea by more quickly restoring the intestinal bacteria required for normal bowel functioning.4

Irritable Bowel Syndrome (IBS)

Irritable Bowel Syndrome (IBS) is a chronic condition which causes very uncomfortable intestinal symptoms. Research has revealed that S. boulardii can reduce the pain, cramping, bloating and excessively frequent bowel movements for a large percentage of those with IBS.5

Irritable Bowel Disease (IBD)

Inflammatory Bowel Disease (IBD) primarily consists of Crohn’s Disease and Ulcerative Colitis. Both of these are extremely painful conditions which cause damage to the intestinal tract. S. boulardii acts as an anti-inflammatory agent in the intestinal tract and has been shown to prevent flares in Crohn’s Disease, as well as excessively frequent bowel movements and intestinal inflammation in Ulcerative Colitis.6,7

Clostridium Difficile

Clostridium difficile (C. diff.) is a bacteria that many carry inside their intestinal tract. In a small percentage of children and adults, C. diff. can create dangerous secondary infections which are especially common after receiving antibiotic therapy in the hospital. Since antibiotics can create this infection, it is extremely challenging to treat. Fortunately, S. boulardii has been found to reduce rates of C. diff. infections in hospitalized adult and pediatric patients on antibiotics.8,9,10

Helicobacter Pylori

Helicobacter pylori (H. pylori) is a bacteria that causes stomach, and sometimes small intestine ulcers. H. pylori has been also linked to stomach cancer in susceptible individuals. S. boulardii has been shown to eradicate this bacteria.11

How can it Help Autoimmune Gastritis?

Builds a Better Intestinal Barrier

S. boulardii can do more than help autoimmune gastritis; it can actually heal it. By strengthening the tight junctions between cells, S. boulardii strengthens the walls of your intestines and makes them a better barrier against infection.4

Raises IgA (Immunoglobulin A) Levels

Another way S. boulardii heals autoimmune gastritis is by raising IgA levels. IgA, or Immunoglobulin A, is one of the main antibodies that lines the intestinal tract to protect us from infection. Sadly, it often becomes impaired or weakened. S. boulardii supplementation has been shown to boost levels of this critical substance.13

Helps Digest Disaccharides

Disaccharides are sugars, such as lactose or fructose, which can be hard to digest when the intestinal tract is not working right. This is because of a lack of disaccharidase, the enzyme needed to process disaccharides, and is often why people struggle to properly digest good carbohydrates, like beans or vegetables. Adding S. boulardii to your regimen will help your body produce more of this enzyme and lead to better carbohydrate digestion.12

Reduces Inflammation

S. boulardii reduces inflammation throughout the intestinal tract. This helps give the cells that line the intestinal tract the chance to repair autoimmune gastritis and rebuild the villi (or tiny, hair-like projections) to increase nutrient absorption. When the gut is less inflamed, autoimmune conditions also improve.13,14,15

Benefits Beyond Skin and Intestinal Health

The benefits don’t end with improved skin and intestinal health. Since S. boulardii is such a strong anti-inflammatory agent, it can act pretty powerfully throughout your body, improving your immune function, reducing food allergies, lowering your risk of infection and increasing the nutrients your body is able to absorb from food.16

Many Advantages of Saccharomyces Boulardii as a Probiotic

Overall, S. boulardii makes an effective probiotic because it creates mannan-oligosaccharides (MOS). These are compounds that prevent harmful bacteria from adhering to the intestinal tract, as it inactivates harmful strains of yeast. Because it’s strong enough to survive stomach acid and protein-digesting enzymes, it’s able to travel to the small and large intestines where it can help. It also is completely safe to take with or instead of bacterial-based probiotics.

It also does not require refrigeration. This is helpful because traveling is one of the most important times to use a probiotic and likely the hardest time to keep one refrigerated.


1 – Weber, G., Adamczyk, A., Freytag, S., “Treatment of Acne with a Yeast Preparation,” Fortschritte der Medizin 107.26 (1989): 563-566, http://europepmc.org/abstract/MED/2530145.
2 – Höchter W., Chase D., Hagenhoff, G., “Saccharomyces boulardii in Acute Adult Diarrhea: Efficacy and Tolerance of Treatment,” Munchener Medizinische Wochenschrift, 132 (1990): 188–192.
3 – McFarland, L.V. “Meta-analysis of Probiotics for the Prevention of Traveler’s Diarrhea,” Travel Medicine and Infectious Disease, 5.2 (2007):97-105.
4 – Czerucka, D., Dahan, S., Mograbi, B., Rossi, B., Rampal, P., “Saccharomyces boulardii Preserves the Barrier Function and Modulates the Signal Transduction Pathway induced in Enteropathogenic Escherichia coli-Infected T84 Cells,” Infection and Immunity, 68.10 (2000): 5998-6004.
5 – Maupas, J., Champemont, P., Delforge, M., “Treatment of Irritable Bowel Syndrome with Saccharomyces boulardii: a Double Blind, Placebo Controlled Study,” Médecine & Chirurgie Digestives, 12.1 (1983): 77-79.
6 – Guslandi, M., Mezzi, G., Sorghi, M., Testoni, P.A., “Saccharomyces boulardii in Maintenance Treatment of Crohn’s Disease,” Digestive Diseases and Sciences, 45.7 (2000):1462-1464.
7 – Guslandi, M., Giollo, P., Testoni, P.A., “A Pilot Trial of Saccharomyces boulardii in Ulcerative Colitis,” European Journal of Gastroenterology & Hepatology, 15.6 (2003): 679-698.
8 – Johnston, B.C., Goldenberg, J.Z., Vandvik, P.O., Sun, X., Guyatt, G.H., “Probiotics for the Prevention of Pediatric Antibiotic-Associated Diarrhea,” Cochrane Database of Systematic Reviews, 11 (2011): CD004827.
9 – Kotowska, M., Albrecht, P., Szajewska, H., “Saccharomyces boulardii in the Prevention of Antibiotic-Associated Diarrhea in Children: a Randomized Double-Blind Placebo-Controlled Trial,” Alimentary Pharmacology & Therapeutics, 21.5 (2005): 583-590.
10 – McFarland, L., Surawicz, C., Greenberg, R., “A Randomized Placebo-Controlled Trial of Saccharomyces boulardii in Combination with Standard Antibiotics for Clostridium difficile Disease,” Journal of the American Medical Association, 271.24 (1994): 1913-1918.
11 – Szajewska, H., Horvath, A., Kołodziej, M., “Systematic Review with Meta-analysis: Saccharomyces boulardii Supplementation and Eradication of Helicobacter pylori Infection,” Alimentary Pharmacology & Therapeutics, 41.12 (2015): 1237-1245.
12 – Buts, J.P., Bernasconi, P., Van Craynest, M.P., Maldague, P., De Meyer, R., “Response of Human and Rat Small Intestinal Mucosa to Oral Administration of Saccharomyces boulardii,” Pediatric Research, 20.2 (1986): 192-196.
13 – Dahan, S., Dalmasso, G., Imbert, V., Peyron, J.F., Rampal, P., Czerucka, D., “Saccharomyces boulardii Interferes with Enterohemorrhagic Escherichia coli-induced Signaling Pathways in T84 Cells,” Infection and Immunity, 71.2 (2003): 766-773.
14 – Buts, J.P., De Keyser, N., De Raedemaeker, L., “Saccharomyces boulardii Enhances Rat Intestinal Enzyme Expression by Endoluminal Release of Polyamines,” Pediatric Research, 36.4 (1994): 522-527.
15 – Thomas, S., Przesdzing, I., Metzke, D., Schmitz, J., Radbruch, A., Baumgart, D.C., “Saccharomyces boulardii inhibits Lipopolysaccharide-Induced Activation of Human Dendritic Cells and T Cell Proliferation,” Clinical and Experimental Immunology, 155.1 (2009): 78-87.
16 – Canani, R.B., Cucchiara, S., Cuomo, R., Pace, F., Papele, F., “Saccharomyces boulardii: a Summary of the Evidence for Gastroenterology Clinical Practice in Adults,” European Review for Medical and Pharmacological Sciences, 15 (2011): 809-822, http://www.europeanreview.org/wp/wp-content/uploads/1000.pdf.

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