Saccharomyces Boulardii: Main Benefits And Side Effects

Saccharomyces Boulardii

There are a lot of microorganisms that can enter the body. While some of these are considered bad and lead to disease, others have beneficial roles to play in the human body.

When looking at probiotics and beneficial microorganisms, people often turn to the good bacteria found in fermented foods and supplements

S. Boulardii is a relatively new addition to the world of beneficial microorganisms, particularly since it only became available as a supplement recently. This is not a bacterium, however. The term Saccharomyces Boulardii rather refers to a particular strain of yeast. It is often used as a medicine in the modern world, assisting with the treatment of certain gastrointestinal problems. 

Benefits Of Saccharomyces Boulardii

The primary reason why some people tend to look for probiotic supplements that contain Saccharomyces Boulardii would be related to the effects that this beneficial yeast species may have in the gastrointestinal tract. 


A study in the World Journal of Gastroenterology provided evidence that a S. Boulardii supplement may be useful in the treatment of conditions associated with diarrhea. A total of 27 previous studies were considered in this research paper. It was found that this particular yeast strain, as part of a probiotic supplement, was effective at treating diarrhea in 84% of reported cases. Among the 27 studies analyzed, there was a total of 5,209 patients involved. 

The study particularly focused on the efficacy of Saccharomyces Boulardii in the treatment of traveler’s diarrhea. Furthermore, the supplement also seems to be highly effective at treating diarrhea caused by antibiotics. 

Ulcerative colitis

People with ulcerative colitis might also be able to benefit from the use of a probiotic supplement with S. Boulardii. One study showed that this probiotic yeast strain should ideally be combined with a drug known as mesalazine. This combination seems to yield an effective way of treating ulcerative colitis. 

Participants in the study experienced a mild or moderate flare-up of symptoms associated with ulcerative colitis. A total of 25 individuals participated in the study. Three servings of a supplement containing Saccharomyces Boulardii was provided to the participants each day. The study lasts for a period of four weeks. A total of 17 of the individuals went into remission by week four. 

For infants?

Under appropriate supervision, the use of a Saccharomyces Boulardii supplement could be beneficial for an infant too. Medical supervision is advised as the safety of the supplement in infants over the long-run has not been confirmed yet.

In one study, a total of 186 infants were considered. Saccharomyces Boulardii supplements were considered a treatment option for some infants with acute diarrhea. The supplement was provided to the infant for a period of five days in total. The duration of the diarrhea symptoms was significantly reduced in those infants who received the Saccharomyces Boulardii supplements. 


The use of Saccharomyces Boulardii probiotics may also yield an anti-inflammatory effect in the human body. This may be useful for certain inflammatory conditions that tend to affect the gastrointestinal tract. An example of such a condition would be irritable bowel syndrome. People with inflammatory bowel disease may also benefit from the use of this probiotic yeast species. 

In addition to these potential benefits, it should be noted that some people use Saccharomyces Boulardii supplements for other purposes too. In particular, it has been found that some people take the supplement to assist in the treatment of acne and canker sores. Reports of people using this probiotic yeast for urinary tract infections have also been noted. 

Side Effects Of Saccharomyces Boulardii

The safety of S. Boulardii has not been considered over a long period of time by scientific studies. At the moment, the supplement is considered safe when used for a short period. Studies still need to consider if the long-term use of the supplement is safe for the human body. 

There are a few potential side effects that have been linked to the use of Saccharomyces Boulardii. Some people tend to experience bloating when they use the supplement. Additionally, the bloating can sometimes be accompanied by gas. 

Concern has previously been raised regarding a potential risk of fungemia in people who use a supplement with Saccharomyces Boulardii. 

Please note: Some people are also advised to be cautious when using the supplement. This would include older people and those with a compromised immune system. The product is also not advised for infants unless specified by a healthcare professional. 

Sources Of Saccharomyces Boulardii

A large number of people tend to prefer opting for a more natural way of obtaining probiotics. With standard good bacteria strains that are often classified as probiotics, a person would generally increase their intake of fermented foods. Probiotic yogurt often comes up as the preferred option for increasing good probiotic strains of bacteria in the gut. 

Things are somewhat different when looking at possible sources of saccharomyces boulardii. This yeast strain is not as readily found within yogurt and other fermented foods. Instead, it is rather found on the skin of certain plants. Two particular plants where the yeast is often extracted from include the mangosteen and the lychee. 

saccharomyces boulardii sources mangosteen and lychee
mangosteen and lychee plants can be saccharomyces boulardii sources

Thus, when it comes to using S. Boulardii as a medicinal product, a person would generally have to consider opting for a supplement that contains this probiotic. It will often not be included in a general probiotic supplement. A person will have to specifically look for a probiotic that lists Saccharomyces Boulardii as an active microorganism. 


While there are some yeast species that can cause infection and problems in the human body, Saccharomyces Boulardii is rather considered a beneficial species. This yeast species is sometimes used as part of medicinal treatment in the human population. It has been linked to benefits in the gastrointestinal tract. Saccharomyces Boulardii is readily available in the form of a supplement today. 

Other probiotic strains


About Ahmed Zayed

MBBch Ahmed gained his medical degree from the University of Alexandria in Egypt. He is a fitness and health enthusiast and is the author of a range of health related books. When he isn't treating patients in hospital he enjoys spending his time raising awareness about public health issues.

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