Lactobacillus reuteri DSM 17938 and Reduced Crying Time

Research synthesisHigh evidenceModerate effect9 studies · 8 beneficial · 1 neutral · 0 harmful

Across 9 studies, 8 reported beneficial effects of Lactobacillus reuteri DSM 17938 on reducing crying time, with effect sizes ranging from small to large. The most robust evidence comes from meta-analyses and RCTs in infants with colic, particularly breastfed infants, showing moderate-to-large reductions (e.g., -45 to -65 minutes/day). Doses of 1×10^8 to 5×10^8 CFU daily were commonly tested, and effects were typically observed within 28 days.

Effective dose range: 1 × 10^8 to 5 × 10^8 CFU daily
Studied populations: infants with colic, breastfed infants, healthy infants

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 largest RCT (n=117) reported a neutral effect on crying time, contrasting with the majority of smaller or meta-analytic studies, suggesting that the benefit may be more pronounced in specific subgroups (e.g., breastfed infants) or that effect sizes are overestimated in the literature.

Generated Jul 9, 2026

Doses used in studies

CFU/day: 100 million–1 billion (median 100 million, IQR 100 million–400 million) — 6 studies

Time to effect

Median: 4 weeks · IQR 4 weeks–4 weeks · Range 4 weeks–4 weeks — Reported in 1 of 9 studies

Safety in these studies

crying timeNo significant differencemean difference = -0.15 (-0.28, -0.01)
Parent-reported crying time (mean difference = -0.15 (-0.28, -0.01)) ... lower in FFI+LR versus FFI-Std
from: Limosilactobacillus reuteri DSM 17938-Containing Infant Formulas and the Associations with
difficulty in passing stoolsNo significant differenceadjusted odds ratio (OR) (95%CI) = 0.46 (0.31-0.68)
Compared with FFI-Std, FFI+LR had lower reports of difficulty in passing stools (11% vs. 22%; adjusted-odds ratio (OR) (95%CI) = 0.46 (0.31-0.68))
from: Limosilactobacillus reuteri DSM 17938-Containing Infant Formulas and the Associations with
fussiness due to spitting-up/vomitingNo significant differencemean difference = -0.17 (-0.29, -0.05)
fussiness due to spitting-up/vomiting (mean difference = -0.17 (-0.29, -0.05)) were lower in FFI+LR versus FFI-Std
from: Limosilactobacillus reuteri DSM 17938-Containing Infant Formulas and the Associations with
hard stoolsNo significant differencemean difference = -0.12 (-0.21, -0.02)
fewer hard stools (mean difference = -0.12 (-0.21, -0.02))
from: Limosilactobacillus reuteri DSM 17938-Containing Infant Formulas and the Associations with
head circumferenceNo significant difference
did not influence infants' head circumference
from: The Efficacy and Safety of the Probiotic Bacterium Lactobacillus reuteri DSM 17938 for Inf
lengthNo significant difference
did not influence infants' length
from: The Efficacy and Safety of the Probiotic Bacterium Lactobacillus reuteri DSM 17938 for Inf
physician-confirmed colicNo significant differenceOR = 0.61 (0.45-0.82)
less physician-confirmed colic (OR = 0.61 (0.45-0.82))
from: Limosilactobacillus reuteri DSM 17938-Containing Infant Formulas and the Associations with
serious adverse eventsNo significant differenceSerious adverse event
was not associated with serious adverse events
from: The Efficacy and Safety of the Probiotic Bacterium Lactobacillus reuteri DSM 17938 for Inf
spitting-up/vomitingNo significant differencemean difference = -0.18 (-0.34, -0.03)
frequency of spitting-up/vomiting (mean difference = -0.18 (-0.34, -0.03)) ... lower in FFI+LR versus FFI-Std
from: Limosilactobacillus reuteri DSM 17938-Containing Infant Formulas and the Associations with
volume of spit-upNo significant differencemean difference = -0.20 (-0.32, -0.08)
volume of spit-up (mean difference = -0.20 (-0.32, -0.08)) ... lower in FFI+LR versus FFI-Std
from: Limosilactobacillus reuteri DSM 17938-Containing Infant Formulas and the Associations with
weightNo significant difference
did not influence infants' weight
from: The Efficacy and Safety of the Probiotic Bacterium Lactobacillus reuteri DSM 17938 for Inf
weight changesNo significant difference
L. reuteri did not influence infants' weight, length or head circumference
from: The Efficacy and Safety of the Probiotic Bacterium Lactobacillus reuteri DSM 17938 for Inf
Overall tolerabilityReported
Regarding safety, this strain maintains an excellent profile supported by its generally recognized as safe (GRAS) status, with no significant adverse effects reported in healthy populations.
from: Efficacy and Safety of Limosilactobacillus reuteri DSM 17938 in Infantile Colic: A Narrati
Overall tolerabilityReported
In addition, L. reuteri did not influence infants' weight, length or head circumference and was not associated with serious adverse events.
from: The Efficacy and Safety of the Probiotic Bacterium Lactobacillus reuteri DSM 17938 for Inf
Overall tolerabilityReported
L reuteri strain DSM 17938 produced no severe adverse events
from: Lactobacillus reuteri for Infants with Colic: A Double‐Blind, Placebo‐Controlled, Randomiz

9 of 9 papersPopulation:

Lactobacillus reuteri for Infants with Colic: A Double‐Blind, Placebo‐Controlled, Randomized Clinical Trial
- 2017-12
- RCT · n = 117
- The Journal of Pediatrics 191
- - Nicole Y. Fatheree
  - Yuying Liu
  - Christopher M. Taylor
  - T. Hoang
  - Chunyan C Cai
  - M. Rahbar
  - M. Hessabi
  - M. Ferris
  - Valarie McMurtry
  - Christine Wong
  - Ta Vu
  - T. Dancsak
  - Ting Wang
  - W. Gleason
  - V. Bandla
  - F. Navarro
  - D. Tran
  - M. Rhoads
- PubMed: 28969890
- DOI: 10.1016/j.jpeds.2017.07.036
7 Insights on
- Reduced Crying Time
- High evidence
L reuteri strain DSM 17938 produced no severe adverse events and did not significantly change crying time
Effect
Neutral
Effect size
Small
Significant
No
Dose
5 × 10^8 colony-forming units daily
The Efficacy and Safety of the Probiotic Bacterium Lactobacillus reuteri DSM 17938 for Infantile Colic: A Meta-Analysis of Randomized Controlled Trials
- 2015-10-28
- Meta-Analysis
- PLOS ONE 10(10)
- - Man Xu
  - Jiao Wang
  - Ning Wang
  - Fei Sun
  - Lin Wang
  - Xiao-hong Liu
  - Vincenzo Lionetti
- PubMed: 26509502
- DOI: 10.1371/journal.pone.0141445
23 Insights on
- Reduced Crying Time
- High evidence
- Rigorous Journal
- Infants
Lactobacillus reuteri decreased crying time (min/d) at three weeks (WMD = -45.83; 95% CI: -59.45 to -32.21; P = 0.000)
Effect
Beneficial
Effect size
Large
Significant
Yes
Dose
Not stated
Probiotics for infantile colic: Is there evidence beyond doubt? A meta-analysis and systematic review.
- 2023-11-14
- Meta-Analysis
- Acta paediatrica (Oslo, Norway : 1992) 113(2)
- - Sáskia Ribeiro Vaz
  - Marise Helena Tofoli
  - Melissa Ameloti Gomes Avelino
  - Paulo Sérgio Sucasas da Costa
- PubMed: 37962097
- DOI: 10.1111/apa.17036
1 Insight on
- Reduced Crying Time
- High evidence
- Clinical
the reduction was ... -64.66 min for Lactobacillus reuteri DSM 17938 (p = 0.03)
Effect
Beneficial
Effect size
Moderate
Significant
Yes
Limosilactobacillus reuteri DSM 17938-Containing Infant Formulas and the Associations with Gastrointestinal Tolerance: A Cross-Sectional Observational Study
- 2023-01-19
- Observational · n = 1,731
- Nutrients 15(3)
- - L. Lavalle
  - N. Sauvageot
  - C. Cercamondi
  - I. Janković
  - D. Egli
  - Y. Vandenplas
- PubMed: 36771237
- DOI: 10.3390/nu15030530
14 Insights on
- Reduced Crying Time
- High evidence
- Infants
Parent-reported crying time (mean difference = -0.15 (-0.28, -0.01)), frequency of spitting-up/vomiting (mean difference = -0.18 (-0.34, -0.03)), volume of spit-up (mean difference = -0.20 (-0.32, -0.08)) and fussiness due to spitting-up/vomiting (mean difference = -0.17 (-0.29, -0.05)) were lower in FFI + LR versus FFI-Std and similar to BFI.
Effect
Beneficial
Effect size
Small
Significant
Yes
Lactobacillus reuteri DSM 17938 Probiotics May Increase CC-Chemokine Receptor 7 Expression in Infants Treated With for Colic
- 2019-07-16
- RCT · n = 50
- Frontiers in Pediatrics 7
- - F. Savino
  - I. Galliano
  - Andrea Savino
  - V. Daprá
  - P. Montanari
  - Cristina Calvi
  - M. Bergallo
- PubMed: 31380326
- DOI: 10.3389/fped.2019.00292
4 Insights on
- Reduced Crying Time
- High evidence
After 28 days, daily mean crying time decrease statistically in the probiotic group: 78 (23) vs. 232 (31), respectively (p < 0.001).
Effect
Beneficial
Effect size
Large
Significant
Yes
Dose
1 × 10^8 CFU daily
Efficacy of a standardized extract of Matricariae chamomilla L., Melissa officinalis L. and tyndallized Lactobacillus acidophilus (HA122) in infantile colic: An open randomized controlled trial.
- 2017-06-30
- RCT · n = 60
- Neurogastroenterology and motility 29(12)
- - M Martinelli
  - D Ummarino
  - F P Giugliano
  - E Sciorio
  - C Tortora
  - D Bruzzese
  - D De Giovanni
  - I Rutigliano
  - S Valenti
  - C Romano
  - A Campanozzi
  - E Miele
  - A Staiano
- PubMed: 28665038
- DOI: 10.1111/nmo.13145
1 Insight on
- Reduced Crying Time
- High evidence
- Infants
At day 28, 39 of 57 (68.4%) of infants in Group C responded to the treatment compared with 57 out of 60 patients (95%) of Group A and 51 out of 59 (86.4%) of Group B (P<.001).
Effect
Beneficial
Effect size
Large
Significant
Yes
Nutraceuticals and Pain Disorders of the Gut-Brain Interaction in Infants and Children: A Narrative Review and Practical Insights.
- 2024-01-25
- Review
- Nutrients 16(3)
- - Silvia Salvatore
  - Mariagrazia Carlino
  - Simona Sestito
  - Daniela Concolino
  - Massimo Agosti
  - Licia Pensabene
- PubMed: 38337634
- DOI: 10.3390/nu16030349
5 Insights on
- Reduced Crying Time
- Moderate evidence
- Rigorous Journal
- Clinical
Significant reductions in colic episodes and crying time were reported ... in one study on Mentha piperita
Effect
Beneficial
Effect size
Moderate
Significant
Yes
Dose
10^8 CFU/day
Efficacy and Safety of Limosilactobacillus reuteri DSM 17938 in Infantile Colic: A Narrative Review From Pathogenesis to Clinical Practice.
- 2026-04-27
- Review
- Cureus 18(4)
- - Kimberly Carvajal Méndez
  - Ana Gabriela Álvarez Barrientos
  - Freddy Gutiérrez Rivera
  - Daniel Aragón Leiva
  - Dennis Ulate Fuentes
- PubMed: 42211616
- DOI: 10.7759/cureus.107824
1 Insight on
- Reduced Crying Time
- Low evidence
- Clinical
Clinical evidence from large-scale meta-analyses confirms that L. reuteri DSM 17938 is significantly superior to placebo, particularly in breastfed infants, where it is twice as likely to achieve a 50% reduction in crying time within 14-21 days of treatment.
Effect
Beneficial
Effect size
Large
Significant
Yes
Probiotics in Functional Gastrointestinal Disorders.
- 2024-01-01
- Review
- Advances in experimental medicine and biology 1449
- - Iva Hojsak
- PubMed: 39060737
- DOI: 10.1007/978-3-031-58572-2_10
2 Insights on
- Reduced Crying Time
- Low evidence
The strongest evidence exists for the use of Limosilactobacillus (L.) reuteri DSM 17938 and Bifidobacterium animalis subsp. lactis BB-12 for the treatment of infantile colic in breastfed infants.
Effect
Beneficial
Effect size
Moderate
Significant
Yes