What is Saccharomyces Boulardii (S.Boulardii)?

Saccharomyces Boulardii is a type of probiotic yeast that belongs to the Saccharomyces cerevisiae family. However, an important distinction to make is that S. boulardii is genetically and functionally distinct from brewer's yeast (S. cerevisiae) This particular strain is a tropical yeast first isolated from lychee and mangosteen fruit peel in 1923 by French scientist Henri Boulard[i].

Probiotics are commonly referred to as "good bacteria" as they mimic the role of beneficial bacteria that are naturally present in our bodies. They aid in combating harmful bacteria and promote digestion and absorption of nutrients. Saccharomyces boulardii is a type of probiotic with a significant distinction: it is not a type of bacteria but rather a yeast that performs the same probiotic functions in the body. Acidic environments, high temperatures, bile, and digestive enzymes do not deactivate it, which means it can reach the intestines alive. It has many benefits to the body and can help improve, and prevent many cases of intestinal distress. Read on to see how S. boulardii can benefit you if supplemented.

What does S.Boulardii do in the body?

Its probiotic properties encompass a broad range of activities, such as enhancing gut health, generating antimicrobial effects, boosting the immune system and preventing inflammation. S. boulardii is primarily employed for managing gastrointestinal disorders, particularly diarrhoea. Read on to discover the benefits, adverse effects, and precautions associated with S. boulardii, as well as the key factors to consider when selecting an S. boulardii supplement.

This article discusses the uses, side effects, and precautions of S. boulardii. It also covers what to look for in a good S. boulardii supplement.

Gut health benefits of S.Boulardii

Saccharomyces boulardii is commonly used for gastrointestinal disorders such as the following[ii]:

Traveller’s diarrhoea

Antibiotic-associated diarrhoea

Irritable bowel syndrome (IBS)

Crohn’s disease

Ulcerative colitis

Traveller’s diarrhoea

This occurs when a person drinks contaminated food or water, usually while in a different country. Several studies have found significant benefits in reducing and helping to resolve cases of traveller’s diarrhoea[iv][v][iii].

Antibiotic-associated diarrhoea

According to a 2020 review, there is evidence that S. boulardii may help prevent antibiotic-associated diarrhoea by helping to restore a person’s gut flora after the medication has been taken. As it is yeast, antibiotics do not kill it, which means a person can take antibiotics and S. boulardii at the same time[vii][vi].

Irritable bowel syndrome

Saccharomyces boulardii is a widely used fungal probiotic in treating various digestive diseases, including irritable bowel syndrome (IBS), which is often used as an umbrella term for a collection of bowel-related symptoms. Saccharomyces boulardii is thought to improve IBS by helping to restore proper movement of the gut wall, thus reducing IBS symptoms such as spasms, gas and diarrhoea[viii].

Intestinal permeability

Intestinal permeability is a term describing the control of material passing from inside the gastrointestinal tract through the cells lining the gut wall. This process is natural, however in disease states, unwanted substances may pass into the blood stream and further inflammation in the body. This is often referred to as ‘leaky gut’. As seen in a study, patients with Crohn's disease in remission, S. boulardii resulted in improvements in intestinal permeability, while those receiving placebo experienced an increase in permeability over the study period [vi].

Irritable Bowel Disease (IBD): Crohn’s disease and Ulcerative Colitis

Several studies have seen improvements in conditions relating to IBD, including Crohn’s disease and ulcerative colitis[xi] [xii][ix][x].

Antibiotic use

Evidence supports use of S. boulardii whilst taking antibiotics to negate negative prescription. In a study of 193 patients, administration of S. boulardii (1000 mg per day) from the beginning of antibiotic treatment and continued for 3 days after the course, significantly prevented the occurrence of diarrhoea compared to placebo [vii].

Cardiovascular disease

In a study, a daily supplement of the probiotic S boulardii (1000 mg per day) for 3 months, resulted in a marked improvement in cardiovascular health markers compared with those taking a placebo [viii].

Candida

Candida is yeast naturally occurring in our bodies, however in cases of overgrowth, it can cause disease. S. boulardii produces capric, caprylic and caproic acids which can help to prevent the proliferation of candida yeasts. A study found S boulardii to reduce candida infections and to lessen the inflammatory host response associated with symptoms of candida overgrowth [ix] [x].

Other uses of S. Boulardii

Lowering High cholesterol

Combating Helicobacter pylori (H. pylori) infection

Combating Clostridium difficile infection [xiii] [xiv]

Precautions

When it comes to safety, there are certain considerations that should be taken into account, such as pregnancy, breastfeeding, children, older adults, individuals with digestive tract disorders or weakened immune systems, and those with yeast allergies. Common side effects of S. boulardii include bloating and flatulence, while a rare but severe side effect may occur in people with multiple severe medical conditions or central venous catheters, leading to fungal blood infections[xv] [xvi].

Interactions:

If an antifungal medication needs to be taken concurrently with S. boulardii, it is suggested that the two be separated by at least four hours apart[xvii].