A nearly 900-child strong Canadian study led by a University of Calgary researcher has determined that commercially available brands of probiotics have no effect on children with intestinal infections.

Dr. Stephen Freedman, a pediatric emergency medicine physician and an associate professor at the University of Calgary’s Cumming School of Medicine, oversaw Canada’s largest clinical trial of the effects of probiotics on children.

The study began in 2013 and took place in six sites across the country including Halifax and Calgary. Half of the 886 subjects, who ranged in age from three months to 48 months, were provided with probiotics while the others received a placebo.

Freedman also served as the co-principal investigator for a concurrent study in the United States involving nearly 1,000 children.

“These were the two largest clinical studies on the use of probiotics in children with diarrheal disease and both studies found very, very remarkably similar results,” explained Freedman. “There was no benefit, in terms of outcomes, in children who had vomiting or diarrhea when they came into the emergency department.”

“Parents really do want to know ‘Do probiotics really work?’ and I think that these two studies really conclusively answer the question that they don’t work for diarrhea of infectious etiologies in kids.”

According to Freedman, the studies’ results are significant given the majority of research in the field has been industry funded and conducted on a much smaller scale.

“There are a lot of claims that probiotics are allowed to make without any evidence of benefit. There are four generally accepted claims that are allowed by, and permitted by, Health Canada and the National Product Directory related to probiotics including good for your gastrointestinal health, intestinal balance, which are very nebulous statements without a lot of clinical meaning. But, as a parent consumer, you’re thinking good for my child’s intestinal balance.”

“This field needs a lot more screening and a lot more clinicians need to really question the recommendations that we are providing.”

He adds that the two studies focused on the effect of probiotics on a singular disease and the results do not speak to other potential benefits of probiotics.

The findings of the Canadian and American studies will be published in the New England Journal of Medicine on Thursday, November 22. The findings of the Canadian study are available below:

With files from CTV’s Jaclyn Brown

Multicenter Trial of a Combination Probiotic for Children with Gastroenteritis by CTV Calgary on Scribd