Lactobacillus reuteri DSM 17938 and Reduced Duration of Diarrhea

Research synthesisModerate evidenceMixed effect size5 studies · 5 beneficial · 0 neutral · 0 harmful

Across 5 studies, all reported beneficial effects of Lactobacillus reuteri DSM 17938 on reducing diarrhea duration, with effect sizes ranging from small to large (predominantly moderate-to-large). Statistically significant findings were observed in 4 out of 5 studies. The most-studied dose was approximately 1-2 × 10^8 CFU/day, primarily in children with acute diarrhea or at risk for antibiotic-associated diarrhea.

Effective dose range: 1 × 10^8 to 2 × 10^8 CFU/day
Studied populations: Children (including those with acute diarrhea, acute otitis media/rhinosinusitis, and healthy children attending day care centers)

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). The evidence base is small (only 5 studies), and one study was a narrative review with no sample size or significance data. Effect sizes varied considerably (small to large), and study durations were not consistently reported.

Generated May 22, 2026

Doses used in studies

CFU/day: 100 million–2 billion (median 150 million, IQR 100 million–650 million) — 4 studies
CFU single-dose: 100 million (median 100 million, IQR 100 million–100 million) — 1 study

Safety in these studies

antibiotic-associated side effectsNo significant differencesignificant decrease of antibiotic-associated side effects
showing 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: an
Overall tolerabilityReported
all 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: an
Overall tolerabilityReported
No adverse events related to the study product were reported.
from: Diarrhea in Preschool Children and Lactobacillus reuteri: A Randomized Controlled Trial
Overall tolerabilityReported
No persistent diarrhoea or severe adverse effects were observed in both groups.
from: Efficacy of Lactobacillus reuteri DSM 17938 in Thai children with acute gastroenteritis an
Overall tolerabilityReported
The study does not report any adverse events or side effects of the intervention.
from: Effect of Limosilactobacillus reuteri DSM17938 to prevent antibiotic-associated diarrhea i

5 of 5 papersPopulation:

Effect of Limosilactobacillus reuteri DSM17938 to prevent antibiotic-associated diarrhea in children: prospective, multi-center, randomized, placebo-controlled clinical trial (PEARL Study).
- 2025-06-09
- RCT · n = 330
- European journal of pediatrics 184(7)
- - Ener Cagri Dinleyici
  - Metehan Ozen
  - Sirin Guven
  - Nazan Dalgic
  - Adem Karbuz
  - Murat Sutcu
  - Ozden Turel
  - Fatma Nur Oz
  - Ulviye Kirli
  - Sevgi Yasar Durmus
  - Ahmet Sami Yazar
  - Zeynep Ebru Cakin
  - Yvan Vandenplas
  - Ates Kara
- PubMed: 40488914
- DOI: 10.1007/s00431-025-06249-8
2 Insights on
- Reduced Duration of Diarrhea
- High evidence
- Large Human Trial
- Clinical
When AAD was observed, the mean duration of diarrhea was longer in the placebo group(p < 0.05).
Effect
Beneficial
Effect size
Small
Significant
Yes
Dose
2 × 10^8 CFU
Diarrhea in Preschool Children and Lactobacillus reuteri: A Randomized Controlled Trial
- 2014-04-01
- RCT · n = 336
- Pediatrics 133(4)
- - P. Gutiérrez-Castrellón
  - G. López-Velázquez
  - Luisa Díaz-García
  - C. Jiménez-Gutiérrez
  - J. Mancilla-Ramírez
  - Juliana Estevez-Jiménez
  - M. Parra
- PubMed: 24639271
- DOI: 10.1542/peds.2013-0652
18 Insights on
- Reduced Duration of Diarrhea
- High evidence
- Large Human Trial
- Highly Cited
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).
Effect
Beneficial
Effect size
Large
Significant
Yes
Dose
10^8 colony-forming unit
Efficacy of Lactobacillus reuteri DSM 17938 in Thai children with acute gastroenteritis and normal or mild dehydration in an outpatient setting: a randomized controlled trial.
- 2025-06-07
- RCT · n = 48
- Journal of tropical pediatrics 71(4)
- - Lakkana Rerksuppaphol
  - Sanguansak Rerksuppaphol
- PubMed: 40618229
- DOI: 10.1093/tropej/fmaf027
5 Insights on
- Reduced Duration of Diarrhea
- High evidence
The median time for diarrhoea to be resolved was significantly shorter in the L. reuteri group compared to the control (48 and 60 h, respectively, P-value = .042).
Effect
Beneficial
Effect size
Moderate
Significant
Yes
Dose
1 × 10^8 CFU/day
Post hoc analysis of fecal samples from responders and non-responders to Lactobacillus reuteri DSM 17938 intervention.
- 2020-09-01
- RCT · n = 44
- Acta biochimica Polonica 67(3)
- - Henryk Szymanski
  - Piotr Mlynarz
  - Badr Qasem
  - Agnieszka Korzeniowska-Kowal
  - Bogumiła Szponar
  - Małgorzata Kałwak-Baran
  - Hania Szajewska
- PubMed: 32945647
- DOI: 10.18388/abp.2020_5344
3 Insights on
- Reduced Duration of Diarrhea
- High evidence
- Children
Responders were defined as subjects with diarrhea lasting no longer than 48 h.
Effect
Beneficial
Effect size
Large
Significant
Yes
Use of Limosilactobacillus reuteri DSM 17938 in paediatric gastrointestinal disorders: an updated review.
- 2022-08-03
- Review
- Beneficial Microbes 13(3)
- - V. Dargenio
  - F. Cristofori
  - C. Dargenio
  - P. Giordano
  - F. Indrio
  - G. Celano
  - R. Francavilla
- PubMed: 35212258
- DOI: 10.3920/BM2021.0151
19 Insights on
- Reduced Duration of Diarrhea
- Low evidence
This strain can decrease the duration of acute diarrhoea and hospitalization for acute gastroenteritis but does not seem to prevent nosocomial diarrhoea and antibiotic-associated diarrhoea.
Effect
Beneficial
Effect size
Moderate

Lactobacillus reuteri DSM 17938 and Reduced Duration of Diarrhea

Effect of Limosilactobacillus reuteri DSM17938 to prevent antibiotic-associated diarrhea in children: prospective, multi-center, randomized, placebo-controlled clinical trial (PEARL Study).

Diarrhea in Preschool Children and Lactobacillus reuteri: A Randomized Controlled Trial

Efficacy of Lactobacillus reuteri DSM 17938 in Thai children with acute gastroenteritis and normal or mild dehydration in an outpatient setting: a randomized controlled trial.

Post hoc analysis of fecal samples from responders and non-responders to Lactobacillus reuteri DSM 17938 intervention.

Use of Limosilactobacillus reuteri DSM 17938 in paediatric gastrointestinal disorders: an updated review.