Pathogenic Effects of Probiotics in Children With Acute Gastroenteritis

Researchers conducted a study that compared the effects of probiotics vs placebo for the treatment of children with diarrhea secondary to acute gastroenteritis.

Among children with acute gastroenteritis, probiotic treatment with either combination Lactobacillus rhamnosus and L helveticus or L rhamnosus GG alone did not result in a decreased risk for severe disease compared with placebo, according to results of a study published in Clinical Infectious Diseases.

A team of researchers analyzed patient-level data from 2 multicenter randomized, placebo-controlled trials performed in pediatric emergency departments in Canada and the United States. The trials included patients with acute gastroenteritis who were aged 3 to 48 months and had greater than 3 diarrheal episodes in the past 24 hours. In addition, patients had to be symptomatic for less than 72 hours and less than 7 days to be eligible for the Canadian trial and US trial, respectively. Patients were randomly assigned in a 1:1 fashion; those included in the Canadian trial were treated with either a probiotic combination of L rhamnosus and L helveticus or placebo, and those in the US trial were treated with either L rhamnosus GG or placebo. The primary outcome was the development of moderate-to-severe gastroenteritis, defined as a score of equal to or greater than 9 on the Modified Vesikari Scale (MVS) stratified by pathogen group and individual pathogens.

Among a total of 1857 participants who were enrolled, 1565 (84.3%) completed follow-up and provided a specimen for enteropathogen analysis. Enteropathogens were identified in specimens from 928 (59.3%) children, with the most common being norovirus (23.2%), followed by rotavirus (21.0%), and adenovirus (10.4%). Among patients with either of these pathogens, the researchers found no differences in regard to the likelihood of experiencing an MVS score equal to or greater than 9 based on treatment allocation (test for interaction=0.35). In addition, there were no identifiable differences among patients with adenovirus (adjusted relative risk [aRR], 1.42; 95% CI, 0.62-3.23), norovirus (aRR, 0.98; 95% CI, 0.56, 1.74), rotavirus (aRR, 0.86; 95% CI, 0.43-1.71), or those with bacterial enteropathogens (aRR, 1.19; 95% CI, 0.41-3.43).

The researchers noted that the risk for moderate-to-severe acute gastroenteritis was decreased among only patients with no identifiable pathogens who received L rhamnosus GG (aRR, 0.56; 95% CI, 0.35-0.90). Also, patients infected with adenovirus who received combination treatment with L rhamnosus/L helveticus experienced fewer diarrheal episodes (aRR, 0.65; 95% CI, 0.47-0.90).

The study was limited because it was a secondary analysis of studies that evaluated 2 different probiotic treatments. Further limitations were limited generalizability, the possibility that a subset of study patients may not have had a noninfectious etiology for their diarrhea, and potential selection bias.

According to the researchers, “the preponderance of the evidence does not support the notion that there are pathogen-specific benefits associated with probiotic use in children with [acute gastroenteritis].”

Disclosure: One author declared affiliations with biotech, pharmaceutical, and/or device companies. Please see the original reference for a full list of disclosures.


Freedman SB, Finkelstein Y, Pang X-L, et al. Pathogen-specific effects of probiotics in children with acute gastroenteritis seeking emergency care: A randomized trial. Clin Infect Dis. Published online October 1, 2021. doi: 10.1093/cid/ciab876