'No evidence' probiotics help children with intestinal infections, Calgary pediatrician's research finds

A pair of studies conducted in Canada and U.S. found that, despite the marketing claims, there’s no evidence that probiotics are useful in treating children with intestinal infections, says a Calgary pediatrician who led the Canadian research.

Major, long-term studies conducted in Canada and U.S. cast doubt on effectiveness of popular products

Melanie Tibbetts tried giving one of her kids probiotics. She is glad to see a definitive study. (CBC)

A pair of studies conducted in Canada and the United States found that, despite the marketing claims, there's no evidence that probiotics are useful in treating children with intestinal infections, says a Calgary pediatrician who led the Canadian research.

Dr. Stephen Freedman, who teaches at the University of Calgary's Cumming School of Medicine and also works at the Alberta Children's Hospital, led a six-city Canadian study that included almost 900 children over 3½​ years.

"We studied the effects of giving probiotics to hundreds of children whose parents brought them into emergency departments across the country suffering from vomiting and diarrhea," said Freedman.

"We found no evidence that probiotics had any effect on reducing symptoms or helping with recovery."

Dr. Stephen Freedman of the University of Calgary’s Cumming School of Medicine led the six-site study that looked at the effect of probiotics on almost 900 children in Canada. He co-authored a similar study in the United States. (CBC)

On the other hand, the study found no adverse side effects associated with the probiotics, either, Freedman noted.

"They're extremely safe in otherwise healthy children for consumption. The downside in this scenario is, running to the pharmacy, picking up a probiotic and then spending $30 to $50 for a short course of a medicine that provided no benefit," he said.

Although his research didn't investigate whether probiotics are beneficial for longer-term maintenance of gastrointestinal health and balance, Freedman said that's also doubtful.

"The evidence is separate, we didn't study it, but in general it is lacking or weak. And these claims are allowed without scientific evidence to support them," he said.

"I would much rather recommend a healthy lifestyle, which would include young children breast feeding, avoidance of antibiotics unless absolutely necessary, and then really a good, healthy, balanced diet of unprocessed food, fruits and vegetables."

2 large-scale studies 

Researchers tested two commercially-available brands of probiotics in the two studies, one in Canada and the other in the United States.

The U.S. study used Culturelle Probiotics, a product that's widely sold in Canada and the U.S. The Canadian study examined a product called Lacidofil, which is more widely available in Europe but the researchers wanted to study it because there had been some evidence of its effectiveness on lab animals, Freedman said.

The Canadian double-blind randomized study began in 2013, with the children ranging in age from three to 48 months.

The children had three or more episodes of watery stools in a 24- hour period, had vomiting or diarrhea for less than 72 hours, and had received a clinical diagnosis of an acute intestinal infection, the study says.

Half of the children received probiotics while the other half got a placebo.

Freedman was also the co-principal investigator on a 10-site study with 1,000 children done at the same time in the United States, led by pediatrics professor Dr. David Schnadower at the Washington University School of Medicine in St. Louis.

'Found no benefit'

"And we also studied kids who had a bit longer duration of symptoms. So we've now studied kids with shorter symptom duration and those who came in with longer symptoms of vomiting and diarrhea, and both groups found no benefit," he said.

Freedman says most studies into the effects of probiotics have so far been small and industry-financed. It's clear that researchers need to question the role and benefits of probiotics for other health applications, as well, he said.

"In order to better serve families, we need independent research to either prove or disprove the claims marketers are making on health-care products," he said.

"These findings, taken together, are very powerful. The findings show that children treated with probiotics have the exact same outcomes across a large range of symptoms as those given placebo — the probiotics had no effect.

Freedman said the two studies were the largest of their kind undertaken to date.

The Canadian study was funded by the Canadian Institute for Health Research. The U.S. research was paid for by the National Institutes of Health.

Findings from both studies will be published in the New England Journal of Medicine on Thursday.