Probiotics Work for Kids With AGE, Right? Not so Fast!

William T. Basco, Jr., MD, MS


February 01, 2019

Although probiotics are widely used, both in adults and children, there are limited rigorous trial data examining their efficacy, particularly in young children. A recent study specifically sought to better understand their role in the management of acute gastroenteritis (AGE).

The study was conducted in the Pediatric Emergency Care Applied Research Network (PECARN), and 10 sites participated. The participating children were between the ages of 3 months and 4 years. The diagnosis of AGE was made by the providers in the respective emergency departments and essentially required at least three episodes of watery stools per day for 7 or fewer days. Vomiting was measured if it occurred, but was not required for diagnosis. Children with a history of prematurity, indwelling catheter, or any other condition that might raise the risk for complication from the treatment strain were excluded.

The almost 1000 children were randomly divided into either a treatment group that received Lactobacillus rhamnosus GG twice daily for 5 days or a comparison group that received a similar-appearing placebo for the same duration. Symptom scores were similar between the two groups at enrollment. Approximately 45.6% of all the children had stool testing positive for a virus. An additional 15.2% had bacterial stool infections and 1.2% had a parasitic infection. Caregivers completed daily symptom score diaries, and email or telephone contact was maintained for at least 5 days and then longer as needed for those whose symptoms had not resolved. Adverse events were assessed by chart review at the end of the trial.

The main outcome of interest was the development of moderate or severe AGE, as measured by a validated scale. Secondary outcomes included the overall frequency and duration of diarrhea and vomiting, the number of unplanned healthcare visits within 14 days of the enrollment, parental missed work, and household transmission.


There was little difference in the numbers of children in each group who developed moderate to severe AGE by day 14 (11.8% of the treatment group vs 12.6% of the placebo group). Differences in the secondary outcomes were also minimal. For example, the duration of diarrhea was 54.3 hours (medium) in the treatment group vs 52.4 hours in the placebo group. The duration of vomiting was essentially 27 hours in both groups. A total of 4.8% of the treatment group vs 4.5% of the placebo group required hospitalization for their illness, and 59.2% of both groups were febrile. Subgroup analysis did not show a difference in outcomes (primary or secondary) by age. None of the subjects had invasive infection with the test strain. Among the subjects who were virus positive, norovirus was the most prevalent, at 19.6% overall. Rotavirus A was the next most prevalent, at 17.7%, adenovirus was present in 9.1%, and Clostridium difficile was the most common bacterium at 7.4%, followed by Shigella at 5%. All other organisms were present in approximately 1% or less of the sample.


A second trial using very similar methods was also published in the same issue of the New England Journal of Medicine.[2] The second trial tested a combination product containing Lactobacillus rhamnosus R0011 and augmented with a small amount of Lactobacillus helveticus R0052. Both trials enrolled children 3 months to 4 years old, and both trials failed to demonstrate effectiveness.

As noted in an accompanying editorial,[3] the findings of these 2 clinical trials are very different from those of previous trials summarized in a well-publicized Cochrane review,[4] leaving clinicians and parents in a bit of limbo. Although both trials were similarly underpowered to evaluate safety concerns alone, it is reassuring to know that there were limited adverse events in both trials, suggesting that parents who try probiotic products on their own may not be raising the risk to their children. However, the trials taken together do not lend support to the notion of proactive recommendation for these two strains of probiotics, at least at present.


Comments on Medscape are moderated and should be professional in tone and on topic. You must declare any conflicts of interest related to your comments and responses. Please see our Commenting Guide for further information. We reserve the right to remove posts at our sole discretion.