Across 11 studies, 8 reported beneficial effects of Lactobacillus reuteri DSM 17938 on reducing diarrhea, with effect sizes ranging from small to large. The evidence predominantly comes from children with acute gastroenteritis or in daycare settings, with doses typically around 1–4 × 10^8 CFU/day. Median study duration was 5 days (reported in only 1 of 11 studies), indicating short-term use.
Caveats: Available evidence is overwhelmingly positive — clinical literature in this area is subject to publication bias (null-result studies are less likely to be published or indexed). Two meta-analyses and one updated review highlight that not all trials show consistent benefits; the smallest and most recent RCT (2022) found no significant effect, and one RCT from 2019 also reported neutral results, suggesting potential diminishing effect in larger or more recent trials.
Adverse events were similar in both groups.
from: Lack of Efficacy of Lactobacillus reuteri DSM 17938 for the Treatment of Acute Gastroentershowing a significant decrease of antibiotic-associated side effects and a tendency to increase the eradication rate
from: Use of Limosilactobacillus reuteri DSM 17938 in paediatric gastrointestinal disorders: anL. reuteri DSM 17938 is effective, safe, and well-tolerated in outpatient children with acute infectious diarrhea.
from: Lactobacillus reuteri DSM 17938 shortens acute infectious diarrhea in a pediatric outpatieall these studies have shown the excellent safety of LR DSM 17938 even at higher dosages.
from: Use of Limosilactobacillus reuteri DSM 17938 in paediatric gastrointestinal disorders: anNo adverse events related to the study product were reported.
from: Diarrhea in Preschool Children and Lactobacillus reuteri: A Randomized Controlled TrialNo adverse events were recorded.
from: Randomised clinical trial: Lactobacillus reuteri DSM 17938 vs. placebo in children with acNo persistent diarrhoea or severe adverse effects were observed in both groups.
from: Efficacy of Lactobacillus reuteri DSM 17938 in Thai children with acute gastroenteritis anThis study shows that L. reuteri DSM 17938 is effective in decreasing frequency and consistency of stools; and is safe at high doses in patients from 1 month to 5 years of age
from: Lactobacillus reuteri protectis DSM 17938 at high doses versus placebo in children with acThe study does not report any adverse events or side effects associated with L. reuteri administration.
from: Systematic review with meta-analysis: Lactobacillus reuteri DSM 17938 for diarrhoeal diseaNo adverse effects were reported.
from: Lactobacillus reuteri DSM 17938 effectively reduces the duration of acute diarrhoea in hosNo adverse effects related to L. reuteri were noted.
from: Lactobacillus reuteri DSM 17938 shortens acute infectious diarrhea in a pediatric outpatieL. reuteri reduced diarrhoeal outcomes in one RCT; the evidence from another trial was less convincing
Compared with placebo or no treatment, L. reuteri reduced diarrhea duration (four RCTs, n = 347, mean difference, MD -0.87 days, 95% CI [-1.43, -0.31]).
L reuteri DSM 17938 significantly reduced the frequency and duration of episodes of diarrhea and respiratory tract infection at both 3 and 6 months (P < .05).
children receiving L. reuteri had a significantly lower relapse rate of diarrhoea (15% vs. 42%; P < 0.03)
Watery diarrhea persisted in 58.6% in group 2 and in 19.4% of group 1 at 5 days of treatment.
The duration of diarrhea after randomization in both groups was similar (P = 0.6).
more diarrhoea-free children were seen in the L. reuteri than control group after 24 and 48 h (50% versus 5%, p < 0.001) and 72 h (69% versus 11%, p < 0.001).
The percentage of participants who recovered within 48 h was significantly higher in the L. reuteri group (65.2%) compared to the control group (36.0%) [relative risk (RR) 3.33, 95% confidence interval (CI) 1.02-10.89, P-value = .043].
From the 72nd hour of intervention onwards, there was no difference between the two groups in the percentage of children with diarrhea.
Similar results were obtained with the original strain, L. reuteri ATCC 55730
does not seem to prevent nosocomial diarrhoea and antibiotic-associated diarrhoea