Study finds probiotics not effective in treating children with viral intestinal infections

A quick Google search for ‘probiotics’ reveals several websites suggesting the benefits of probiotics for gut health and their efficacy in treating common stomach bugs. However, the published literature on probiotics suggests a much different story.

Researchers from The Hospital for Sick Children (SickKids) and other paediatric hospitals across Canada worked with lead researchers at the University of Calgary and Alberta Children’s Hospital to investigate whether probiotics are effective in treating gastroenteritis – commonly referred to as the stomach flu. After conducting a six-site study across Canada including almost 900 children presenting to Emergency Departments (EDs) with gastroenteritis, the researchers concluded that probiotics had no impact on disease course. The study was published on November 22, 2018 in The New England Journal of Medicine.

“Probiotics are widely consumed by many children and adults in North America owing to widely touted health benefits. However, the evidence to date for gastroenteritis has been controversial,” says Dr. Yaron Finkelstein, SickKids site investigator of the study and Emergency Physician. “As one of two multi-center studies to examine the use of probiotics using rigorous methodology in a large sample of patients, we expect these findings will dramatically change practice.”

Although the quality of previously available evidence in support of using probiotics for gastroenteritis has been classified as “low”, some experts consider probiotics to primarily treat acute infectious diarrhea. Many published studies on probiotics have shown some benefit but had significant methodologic limitations and small sample sizes. The research team led by Dr. Stephen Freedman of the University of Calgary set out to study this question in a large sample using a robust clinical trial design and enlisted six sites across Canada to participate, including SickKids.

The study participants included children who ranged in age from three months to four years and were diagnosed with gastroenteritis in an ED of one of the trial sites. Half of the participants were given a twice-daily dose of probiotics to be taken over five days and half were given an equal amount of a placebo.

Within 14 days of receiving either the probiotics or placebo, 26.1 per cent of patients in the probiotic group and 24.7 per cent of patients in the placebo group showed moderate-to-severe symptoms of gastroenteritis.

“This study provides conclusive evidence that administration of probiotics did not decrease duration of symptoms, frequency of symptoms or frequency of health-care visits in children who were diagnosed with acute gastroenteritis in EDs across Canada,” says Dr. Suzanne Schuh, a senior author and site principal investigator of the study, and an Emergency Physician at SickKids. “We need to cut through the noise about these products with rigorous scientific evidence so clinicians and families can make informed decisions.”

The researchers measured severity of gastroenteritis through a validated composite score of the frequency and duration of symptoms such as diarrhea and vomiting. Further analysis of individual symptoms also showed no significant difference between the probiotics and placebo groups.

This work was supported by the Canadian Institutes of Health Research (CIHR). It is an example of how SickKids is making Ontario healthier, wealthier and smarter.