Probiotics and Diarrhoea

By : Ms Lam Cai Hong, Pharmacist at Unity Hougang 1

First seen in Lifestyle Magazine (May 2013), pg 96. This article is an unbreached version of the print edition.

What is Traveler's diarrhoea?

Travelers’ diarrhoea is caused by consuming contaminated food or water while traveling and occurs in 30-70% travelers. Symptoms range from mild cramps and urgent loose stools to severe abdominal pain, fever, vomiting and bloody diarrhoea. Bacteria are the most common cause, followed by virus and protozoa. Untreated bacterial diarrhoea lasts 3–5 days, viral diarrhoea lasts 2–3 days and protozoal diarrhoea can persist for weeks to months without treatment. An acute bout of gastroenteritis can lead to persistent gastrointestinal symptoms in up to 10% travelers, even in the absence of continued infection.

The most important determinant of risk is travel destination with most of Asia, the Middle East, Africa, Mexico and Central and South America categorized as high-risk areas. Some preventive measures to reduce risk include selecting food that are freshly cooked and beverage that are bottled, sealed, boiled, carbonated or treated with iodine or chlorine, use of probiotics for prevention and carrying small containers of alcohol-based hand cleaners (containing at least 60% alcohol) for easy cleaning of hands before eating.

What are probiotics?

The normal human digestive tract contains about 400 types of probiotic bacteria that maintain the natural balance of organisms (microflora) in the intestines, reduce the growth of harmful bacteria that might cause diseases such as diarrhoea and promote a healthy digestive system. The largest group of probiotic bacteria in the intestine is lactic acid bacteria, of which Lactobacillus acidophilus is the best known. There are dozens of different bacteria and yeasts that may have health benefits. Only certain strains appear to help diarrhoea. And only certain types of diarrhoea appear to respond to probiotics. It still needs to be proved which probiotics (alone or in combination) might reduce both the duration of illness and the frequency of stools. Even the strains of probiotics that have been proved to work for a specific disease are not widely available and subjected to strain stability and survivability issues.

Probiotics may help lower the risk of getting travelers’ diarrhoea. Their effectiveness are however further affected by many factors including various trip destinations, local microflora, eating habits of the travelers, time point (before or during travel) and means (eg as a capsule or a fermented milk product) of administering the probiotics. The strongest evidence pointed to benefits from Saccharomyces boulardii, Lactobacillus acidophilus, Lactobacillus GG and Bifidobacteria bifidum. The strength of probiotic is usually indicated by the number of living organisms per dosage form (eg as a capsule or sachet). Dose that have been studied in scientific research for preventing traveler's diarrhoea is Lactobacillus GG is 2 billion organisms daily.

Is it safe to take?

They are likely safe for most people including babies and children. Side effects are usually mild and most often include intestinal gas or bloating. Caution should however be exercised when administering probiotic supplements to immunocompromised individuals. This includes people with HIV/AIDS or people who have taken medicines to prevent rejection of a transplanted organ. There is some concern that probiotics from supplements that contain live bacteria might grow too well in people whose immune systems are weakened. People with short bowel syndrome might be more likely to develop infections. There are no studies done during pregnancy and breast-feeding, so their safety is unknown.

Can I take with other medicine, supplements and food?

Taking antibiotics along with probiotics can reduce the effectiveness of probiotics as antibiotics can also reduce this 'friendly' bacteria in the body. To avoid this interaction, take probiotics at least 2 hours before or after antibiotics. Medications that decrease the immune system (immunosuppressants) can increase your chances of getting sick from these bacteria and yeast probiotics as the immune system usually controls bacteria and yeast in the body to prevent infections. Some immunosuppressants include azathioprine, cyclosporine, mycophenolate, tacrolimus, sirolimus, basiliximab, daclizumab, muromonab-CD3, prednisone, corticosteroids and others. There are no known interactions with herbs, supplements or foods.