Probiotic Supplements Show No Benefit for Children with Gastroenteritis

The results of a new pair of studies from investigators in the United States and Canada have debunked a previously accepted idea that probiotic supplements are helpful to children with gastroenteritis.

Gastroenteritis leads to 1.7 million pediatric emergency room visits and more than 70,000 hospitalizations in the United States each year. Treatment for these infections typically includes replacing lost fluids and electrolytes; however, previous research has indicated that treatment for healthy infants and children can include supplementation with probiotics, to reduce the severity and duration of symptoms by restoring normal bacterial microflora in the gastrointestinal tract.

Now, investigators on the pair of studies, published in the New England Journal of Medicine, found that probiotic supplements were ineffective at reducing diarrhea and vomiting in children with gastroenteritis.

In the US study, investigators looked at 971 children aged 3 months to 4 years who were treated for gastroenteritis in the emergency departments at St. Louis Children's Hospital or 1 of 9 other academic medical centers around the country between July 2014 and June 2017. To be included in the study, participants could not have received probiotics in the 2 weeks prior to being treated in the emergency department.

Half of the study participants were randomly assigned to receive the probiotic Lactobacillus rhamnosus GG (LGG) twice daily for 5 days, while the others received a placebo, along with standard clinical care.

Children in both groups had nearly identical symptoms and similar recovery time, with diarrhea lasting about 2 days in both groups. A similar study conducted in Canada mirrored the US study’s results.

According to David Schnadower, MD, MPH, who served as associate professor of pediatrics, emergency medicine, Washington University in St. Louis School of Medicine, physician at St. Louis Children’s Hospital, lead author of the US study and co-author of the Canadian study, previous smaller trials have shown some benefit to probiotics, with LGG appearing to be the most promising probiotic for diarrhea, prompting medical societies around the world to recommend the popular supplements. However, those particular trials may not be widely applicable because of their small study populations, the use of different types of probiotics, the lack of blinded studies, and the fact that some studies were supported by the probiotic industry.

“There was no single strong trial that showed…with confidence that they worked or didn’t work, [and] so that’s what prompted us to do this study,” Dr. Schnadower, who is currently the senior academic, director of the Division of Emergency Medicine at Cincinnati Children’s Hospital Medical Center, told Contagion® in an interview. “These 2 studies are large, well-powered, well-done, and have all the bells and whistles of top-notch clinical trials and that’s strong evidence.”

The US study was funded with more than $3 million from the NIH, and was completed independent from the probiotic industry.

According to the investigators, the global market for probiotics is expected to rise from $37 billion in 2015 to $64 billion in 2023; therefore it is critical to determine whether eating probiotic-enriched foods or taking over-the-counter supplements is beneficial to gastrointestinal health.

"The results of the US and Canadian studies were not ambiguous," added the US study's co-author, Phillip I. Tarr, MD, Washington University's Melvin E. Carnahan Professor of Pediatrics and director of the Pediatric Division of Gastroenterology, Hepatology and Nutrition. "Probiotics had no effect on the children. Parents are better off saving their money and using it to buy more fresh fruits and vegetables for their children."