Prevent Traveller’s Diarrhoea with S. Boulardii

Prevent Traveller’s Diarrhoea with S. Boulardii

Of all the species in the microflora, probiotics are of most importance to your body’s health. Probiotics affect many aspects of the body including nutrient digestion and absorption, immunity and much more. Probiotics have many mechanisms of action.
Here are the ways in which probiotics help you:

  • They prevent bad microbes from growing and causing illness.
  • They prevent or inhibit bad microbes by competing for receptor sites, masking sites and making the gut environment acidic.
  • They produce enzymes that promote health.
  • They produce antimicrobials that kill bad microbes.
  • They support the health of cells that line the intestines.
  • They work synergistically and positively affect the immune system.

Probiotics can be used as prevention against infection, for instance, Traveller’s Diarrhoea (TD).

Travellers’ diarrhoea or TD affects travellers who consume food or water that their system doesn’t agree with. It typically causes loose stools and abdominal cramps. Most of the time, it’s caused by bacteria, but sometimes viruses or parasites are to blame. When you visit a place where the climate or sanitary practices are different from yours at home, you have an increased risk of developing traveller’s diarrhoea. Travellers’ diarrhoea affects between 30% and 70% of travellers, depending on the destination and the season. It is especially common in humid climates, where bacteria breed more easily.

Common signs and symptoms
Traveller’s diarrhoea may begin abruptly during your trip or shortly after you return home. Most people improve within 1 to 2 days without treatment and recover completely within a week. However, you can have multiple episodes of traveller’s diarrhoea during one trip. The most common symptoms are:

  • Sudden onset of three or more looser watery stools a day
  • An urgent need to defecate
  • Abdominal cramps
  • Nausea
  • Vomiting
  • Fever

If you get moderate to severe dehydration, bloody stools, or severe pain in the abdomen or rectum, as also fever that lasts for a few days, it’s time to see a doctor.

Causes of Traveller’s Diarrhoea

Poor hygiene practice – According to Centers for Disease Control and Prevention (CDC), traditionally, it was thought that Traveller’s Diarrhoea could be prevented by following simple recommendations such as ‘Boil it, cook it, peel it, or forget it’, but studies have found that people who follow these rules may still become ill. Poor hygiene practice in local restaurants is likely the largest contributor to the risk for Traveller’s Diarrhoea.

Warmer climate – In environments in warmer climates where large numbers of people do not have access to plumbing or latrines, the amount of stool contamination in the environment will be higher and more accessible to flies.

Inadequate electrical supply – This may lead to frequent blackouts or poorly functioning refrigeration, which can result in unsafe food storage and an increased risk for disease.

Lack of safe water – It may lead to contaminated foods and drinks prepared with such water; inadequate water supply may lead to shortcuts in cleaning hands, surfaces, utensils, and foods such as fruits and vegetables. In addition, handwashing may not be a social norm and could be an extra expense. There may be no handwashing stations in food preparation areas.

The infections that cause Traveller’s Diarrhoea

According to Cleveland Clinic, the most common causes are bacteria, especially E. coli. Other common bacteria include:

  • Salmonella
  • Cholera
  • Campylobacter jejuni and
  • Shigella.

Viral infections may include:

  • Norovirus
  • Rotavirus and
  • Astrovirus.

Parasite infections may include:

  • Giardia.
  • Cryptosporidium and
  • Cyclospora.

Possible complications of Traveller’s Diarrhoea

  • The loss of body fluid from diarrhea and vomiting can lead to dehydration. This can be serious.
  • A small number of people can develop post-infectious irritable bowel syndrome. This can cause symptoms such as:
  • Long-term diarrhoea
  • Belly pain and cramping
  • Bloating.

How to prevent Traveller’s Diarrhoea

For travellers to high-risk areas, there are several steps that can reduce the risk for Traveller’s Diarrhoea:

  • Only use water that has been boiled or chemically disinfected for drinking, making tea or coffee, brushing your teeth, washing fruits and vegetables, washing food utensils and equipment, and washing the surfaces of food or drink tins, cans, and bottles.
  • Avoid eating raw fruits, vegetables, or salad greens, raw meat, shellfish, condiments that are left on the table, such as ketchup, mustard, sauces, or dips.
  • Avoid drinking unpasteurised milk, or having other dairy products like cheese, ice cream, or yogurt.
  • Don’t eat street foods or food from unknown sources.
  • Avoid adding ice to drinks.
  • Only have drinks that are bottled and sealed.
  • Use drinking straws instead of drinking directly from glasses or cups.
  • Take antibiotic or antidiarrheal medicine advised by your doctor.

S. Boulardii to prevent Traveller’s Diarrhoea

S. boulardii is a live yeast used extensively as a probiotic and several mechanisms of its action have been identified. It works against pathogenic microorganisms, regulates and maintains the intestinal microbial homeostasis, interferes with the ability of pathogens to colonise and infect the mucosa, modulates local and systemic immune responses, stabilises the gastrointestinal barrier function and is known to play a role in the induction of enzymatic activity favouring absorption and nutrition.

According to research published in the journal ‘Therapeutic Advances in Gastroenterology’, S. boulardii has been tested for clinical efficacy in several types of acute gastrointestinal conditions, including antibiotic-associated diarrhoea, acute diarrhoea, enteral nutrition-related diarrhoea, traveller’s diarrhoea and Helicobacter pylori infection. A 2006 meta-analysis published in the ‘American Journal of Gastroenterology’ showed a significant reduction in the prevention of Traveller’s Diarrhoea when probiotics like S. boulardii were used. Says the study published in the ‘Therapeutic Advances in Gastroenterology’, S. boulardii mediates effects which resemble the protective effects of the normal healthy gut flora. It notes that no adverse effects were observed in any of the clinical trials.

The choice of a high-quality probiotic product is one of the most important factors that determines the efficacy of the probiotic. Selecting high-quality probiotic products will improve your chances of better health. Look for freeze-dried S. boulardii products. They are stable at room temperature, have the advantage of portability and maintain high viability counts over prolonged periods. A 1998 study found that a freeze-dried product outperformed three heat-killed S. boulardii preparations in terms of pharmacokinetics and higher number of viable cells.


Several clinical trials and studies strongly suggest a place for S. boulardii for the prevention and treatment of gastrointestinal diseases. S. boulardii mediates responses that resemble the protective effects of the normal healthy gut flora. The multiple mechanisms of action of S. boulardii and its properties explain its efficacy and beneficial effects in acute and chronic gastrointestinal diseases. 


Ther Adv Gastroenterol (2012) 5(2) 111–125. DOI: 10.1177/

McFarland, L.V. (2006) Meta-analysis of probiotics for the prevention of antibiotic associated diarrhea and the treatment of Clostridium difficile disease. Am J Gastroenterol 101: 812–822. 

Schwenzer, V.B. (1998) Saccharomyces boulardii. Deutsche Apotheker Zeitung 138: 75–77.

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