While patterns of diseases worldwide are constantly changing, diarrhoea remains a leading cause of mortality among children younger than five years. Diarrhoea is usually a symptom of an infection in the intestinal tract, which can be caused by a variety of bacterial, viral, and parasitic organisms. Infection is commonly spread through contaminated food or drinking-water, or from person to person as a result of poor hygiene. 

Diarrhoea can last several days and can leave the body without the water and salts that are necessary for survival.

Common consequences of diarrhoea, dehydration and fluid loss can be dangerous, particularly in children. As such, it’s important for patients to replace the water and electrolytes their body loses when they’re suffering from diarrhoea. While the management of acute diarrhoea involves the replacement of these lost fluids with glucose-electrolyte oral rehydration solution, as Dr Roberto Berni Canani et al. explained in Probiotics for treatment of acute diarrhoea in children: a randomised clinical trial of five different preparations (published in The BMJ), this solution reduces neither the severity nor the duration of diarrhoea. “The search for such agents started over 20 years ago. Probiotics, defined as micro-organisms that exert beneficial effects on human health when they colonise the bowel, have been proposed as adjunctive therapy in the treatment of acute diarrhoea.  

“Several micro-organisms are effective in reducing the severity and duration of acute diarrhoea in children: Lactobacillus rhamnosus (formerly ‘Lactobacillus GG’), L plantarum, several strains of bifidobacteriaEnterococcus faecium SF68, the yeast Saccharomyces boulardii, and preparations containing a mix of strains,” the authors reported. “Probiotics have progressively gained in credibility for the treatment of diarrhoeal diseases.” In fact, a study of Italian children with diarrhoea found probiotics to be the most commonly prescribed treatment.  

THE SCIENTIFIC EVIDENCE 

While randomised double-blind studies have provided evidence of probiotic effectiveness for the treatment and prevention of acute diarrhoea and antibiotic-induced diarrhoea, according to doctors Barry Goldin and Sherwood Gorbach (Clinical Indications for Probiotics: An Overview, published in Clinical Infectious Diseases), research studies have also shown evidence of effectiveness for the prevention of traveller’s diarrhoea. Furthermore, several studies are emphasising the role that probiotics have in treating not just diarrhoea, but the intestinal impairment after the infection too.  

ACUTE VIRAL DIARRHOEA 

“Worldwide, the most frequent causative pathogen for infectious diarrhoea is rotavirus,” Prof Donald Cameron et al. warned in Probiotics for gastrointestinal disorders (published in the World Journal of Gastroenterology). “It’s responsible for approximately 40% of all hospital admissions for diarrhoea of infants and young children.”  

In a trial published in Clinical Infectious Diseases, Dr Kulandaipalayam Sindhu et al. reported that reviews of certain probiotics showed benefit in acute rotavirus diarrhoea, with a significant reduction in duration. “Studies suggest that probiotics modulate the innate and adaptive immune response, particularly in the gastrointestinal tract, and intestinal barrier function. A few studies have shown that probiotics have a positive effect on intestinal permeability.” The positive immunomodulatory effect of certain probiotics may also be useful in decreasing reinfections.  

ANTIBIOTIC-ASSOCIATED DIARRHOEA 

Diarrhoea is the most common side effect of antimicrobial therapy, in fact, diarrhoea occurs in approximately 20% of patients who receive antibiotics, Dr Philippe R Marteau et. al. reported in Protection from gastrointestinal diseases with the use of probiotics (published in The American Journal of Clinical Nutrition, Volume 73). “Antibiotic-associated diarrhoea (AAD) results from a microbial imbalance that leads to a decrease in the endogenous flora that is usually responsible for colonisation resistance and to a decrease in the fermentation capacity of the colon. Controlled trials indicate a benefit of [several probiotics] in the prevention of AAD.  

TRAVELLER’S DIARRHOEA 

People travelling to warmer climates and less-developed countries experience a high incidence of diarrhoea, often in the 50% range. Even small attacks can interrupt a holiday, which explains the interest the travelling public has in medications that could be used to prevent traveller’s diarrhoea. “A safe, inexpensive, and effective drug against traveller’s diarrhoea would have important public health implications,” Dr Rial Rolfe said in The role of probiotic cultures in the control of gastrointestinal health (published in The Journal of Nutrition, Volume 130). “Several probiotics have been examined for their ability to prevent traveller’s diarrhoea, including Lactobacillus, Bifidobacterium, Streptococcus and Saccharomyces  

The use of probiotics in medical practice is rapidly increasing, as are studies that demonstrate their efficacy. Probiotic agents are becoming an important part of the armamentarium against gastrointestinal problems.