What is S-Boulardii

Saccharomyces boulardii (S. boulardii) is a tropical yeast strain that has been found to act as a probiotic when ingested and replenishes gastrointestinal flora, and gut health. This yeast grows at body temperature, and is a non-pathogenic organism, meaning that it does not cause disease in humans.

It is also non-systemic, meaning it is limited to the digestive tract and does not spread throughout the body.

Traditional Uses for S-Boulardii

Traditionally, S. boulardii was ingested by people in South-East Asia, as a folk medicine to prevent and treat diarrhea of various causes, particularly cholera.

To ingest this yeast, they chewed the skins of the mangosteen and lychee fruits, upon which S. boulardii has been shown to cultivate naturally. Because it is in the yeast family, it is inherently resistant to antibacterial antibiotics, and thus is a great choice of probiotic for treatment alongside these antibiotics to help reduce their unintended side effects.

Key Benefits of S-Boulardii

Traveller's Diarrhea

In general, probiotics are beneficial microorganisms that coat the digestive tract much like the grass on your lawn. Seeding the lawn with a wide variety of beneficial grass creates a strongly rooted lawn that prevents weeds from growing. In the same way, seeding your gut with a wide variety of probiotics helps to ensure that any pathogenic organisms, such as bacteria that cause diarrhea, or the pathogenic yeast Candida albicans (the yeast that causes human yeast infections) cannot take hold. Research has shown that S. boulardii can inhibit the growth of pathogenic organisms such as Candida albicans, E. coli, Shigella spp., Salmonella, Pseudomonas, and Staphylococcus. In addition to helping prevent infection by these organisms, S. boulardii has been proven to prevent antibiotic-associated diarrhea in several clinical trials, and is effective in preventing 2/3 of cases of traveler's diarrhea when taken at least 5 consecutive days prior to exposure.

S. boulardii and IBD (Crohn's and Ulcerative Colitis)

Interestingly, current research is beginning to examine the role of this probiotic in protecting against gut inflammation. It has been found to decrease the amount of a proinflammatory cytokine called Interleukin 8 (IL-8), which could allow it to have a protective effect in inflammatory bowel disease. More research is required in this area before we can be sure of this protective effect.

S. Boulardii and C. Difficile

Clostridium difficile (C. difficile, or C. diff) is an extremely antibiotic-resistant organism that tends to cultivate in a hospital and clinical environments and infect people undergoing antibiotic treatments or who have compromised immune systems. One of the most exciting pieces of information to come out of current research on S. boulardii is its ability to protect against C. difficile in a number of different ways. It can reduce the symptoms of a current C. difficile infection by protecting the host against several toxins produced by this pathogenic bacteria. Also, co-supplementation of this probiotic with antibiotics targeted against C. difficile significantly reduced relapse of infection after treatment is completed. There is even preliminary evidence that it may be able to directly treat C. difficile infection, without the use of antibiotics in over 70% of those infected. In fact, the WHO (World Health Organization) has stated that it considers S. boulardii to be a possible treatment for recurrent C. difficile colitis.

Taking S. Boulardii Supplements

Currently, there are several preparations of S. boulardii available in viable freeze-dried formulations. S. boulardii is often marketed as a probiotic in a lyophilized form and in these cases is therefore referred to as Saccharomyces boulardii lyo (one well-known brand is Florastor). The recommended dosage is 750-1000mg of freeze-dried yeast per day in divided doses. Generally speaking, it is better to take probiotics with food to help protect them against your stomach acid so they can cultivate your intestines. Current doses are sufficiently high that capsules can be taken away from food if required. For protection against infection by pathogenic organisms, supplementation should begin at least 5 days prior to exposure.

Important Information

Although extremely rare, a few cases with Saccharomyces boulardii fungemia have been reported in patients with central intravenous lines. Careful use of Saccharomyces boulardii in patients with central lines is recommended.