New study reveals probiotics do not help children with intestinal infections

As a young mom of two growing boys, Melanie Tibbetts often struggles with the decision of how to help them when they’re sick. “Especially, when they can’t really tell you what’s going on,” says Tibbetts, mom of a five-month-old and a three-year-old. “I strive to do what’s best. I read labels at the drugstore looking for clues. There’s so much information out there about gut health and whether probiotics can help them get better when they’re sick.”

New research from the University of Calgary can help sort through the confusion. In the largest clinical trial to date in Canada, researchers found the popular products have no effect on gastroenteritis, commonly yet erroneously called the stomach flu, in children.

“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,” says Dr. Stephen Freedman, MD, paediatric emergency medicine physician with Alberta Health Services, and associate professor in the departments of paediatrics and emergency medicine at the Cumming School of Medicine (CSM). “We found no evidence that probiotics had any effect on reducing symptoms, or helping with recovery.” 

Freedman, below, says more independent research is needed to either prove or disprove the health claims marketers are making on the effectiveness of probiotics, and​ led a six-site study that included almost 900 children. He was also the co-principal investigator on a 10-site, concurrently conducted study in the United States, led by Dr. David Schnadower, MD, that recruited almost 1,000 children. Findings from both studies were published on Nov. 22, 2018 in the New England Journal of Medicine. 

“There were smaller trials that had shown promising results. We wanted to replicate these findings on a large scale to see whether the age of the patient, the type of infection, and the use of antibiotics or length of time a child had the illness would affect the response to probiotics,” says Schnadower, who conducted the research as a professor of paediatrics at Washington University School of Medicine in St. Louis and is now a professor at University of Cincinnati College of Medicine.

“The findings in both studies were consistently negative regardless of how the data were analyzed.”

Researchers tested two commercially available brands of probiotics. Recruitment for the Canadian double-blind randomized study began in 2013. Children ranged in age from three to 48 months. Half of the children received probiotics while the other half received a placebo. 

“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,” says Freedman, who is holder of the Alberta Children’s Hospital Foundation Professorship in Child Health and Wellness, and member of the Alberta Children’s Hospital Research Institute and the O’Brien Institute for Public Health at the CSM.

“The results deliver a clear message that we need to question the role and benefits of probiotics for other health applications using large, patient-oriented, rigorous clinical trials.” 

Probiotics are generally considered safe to use. They are classified as food ingredients in Canada and can be sold as natural health products. As such, they do not require the same rigorous scientific testing that medications require, such as multiple clinical trials, in order to make beneficial claims.

“Until now, most studies into the effects of probiotics have been small and industry funded,” says Freedman. “In order to better serve families we need independent research to either prove or disprove the claims marketers are making on health-care products.”

For Tibbetts, being armed with information is important. “It will help me make a more informed choice for my kids. There’s sometimes a lot of peer pressure to try different products. This research will help me better navigate the drug aisle and well-intentioned advice.”

The Canadian research was supported by the Canadian Institutes of Health Research. The U.S. study was supported by the National Institutes of Health.