Big effect
In a trial of 330 children on antibiotics, a specific probiotic strain halved the risk of diarrhea — but the effect was clearest in kids under two.
This is a well-designed, double-blind trial with a large effect, but it's one of the first on this exact pairing, so the finding needs replication before it's a reliable recommendation.
Children taking the probiotic Lactobacillus reuteri DSM 17938 alongside antibiotics were about half as likely to develop diarrhea compared to those on placebo — 7.9% versus 16.7% at two weeks. The benefit lasted through eight weeks of follow-up and was strongest in children aged 6–24 months or those treated for ear infections, meaning the results may not apply to older kids or other conditions.
Where this fits in the evidence
This is among the first studies we've indexed on Lactobacillus reuteri DSM 17938 for Reduced Antibiotic-Associated Diarrhea — treat it as an early signal until more research accumulates.
The study
- Randomized Controlled Trial (RCT)
- n = 330
- 2025-06-09
- European journal of pediatrics
This is a plain-language summary of a research finding, not medical advice. Pillser surfaces research signals to help you decide what's worth investigating — always consult a qualified professional before changing what you take.