tuneTypical Dose
100000000-10000000000
Microbiome Modulator
Lactobacillus reuteri
Limosilactobacillus reuteri
Evidence TierCWADA NOT PROHIBITED
watchEffect Window
2-4 weeks for colic outcomes. Up to ~8 weeks for H. pylori protocol outcomes.
check_circleCompliance
WADA NOT PROHIBITED
Overview
Clinical Summary
Lactobacillus reuteri is a strain-specific probiotic with the strongest adult evidence as an adjunct during H. pylori eradication therapy.
The clearest human evidence for L. reuteri is adjunctive use during H. pylori eradication, where pooled trials show modest gains in eradication success and tolerability. Infant colic results remain mixed and strongly dependent on strain and feeding context.
Strain-specific probiotic effects on gut ecology and mucosal immune signaling with indication-dependent clinical translation.
Outcomes
What This Is Expected To Influence
Primary Outcomes
- H. pylori eradication support (strain/protocol dependent)
- Infant colic crying/fussing reduction (mixed evidence)
Secondary Outcomes
- GI symptom burden during eradication therapy
- Tolerability/adverse symptom burden during treatment
Safety
Contraindications and Interactions
Contraindications
- Severe immunosuppression without physician guidance
- Critical illness
- Central venous catheter setting without specialist oversight
Side effects
- Bloating
- Gas
- Stool-pattern changes
Interactions
- Antibiotics can reduce viable probiotic exposure
- Multi-strain products may not match single-strain evidence
- Prebiotic combinations can increase initial GI intolerance
Avoid if
- Active sepsis
- Neutropenia
- High invasive infection risk state without clinical supervision
Evidence
Study-level References
lactobacillus-reuteri-SRC-001Meta-analysis of randomized controlled trials
Sourceopen_in_newLi M, Wang X, Dong X, et al. Lactobacillus reuteri compared with placebo as an adjuvant in Helicobacter pylori eradication therapy: a meta-analysis of randomized controlled trials. Therap Adv Gastroenterol. 2024;17:17562848241258021. doi:10.1177/17562848241258021. PMID:38846173.
Population: Patients receiving H. pylori eradication therapy across eight randomized controlled trials.
Dose protocol: Eight randomized placebo-controlled eradication trials pooled in meta-analysis
Key findings: Improved eradication rate, reduced GI symptoms, and lowered adverse-event burden versus placebo.
Notes: Better anchor than any single eradication trial because it pools multiple regimens.
Paper content
This 2024 meta-analysis strengthens the adult use case for L. reuteri more than any single eradication trial. Across eight randomized studies, adjunctive L. reuteri modestly improved H. pylori eradication rates, reduced GI symptoms, and lowered antibiotic-related adverse events. That supports keeping eradication support as the main evidence-backed indication while still emphasizing strain and protocol dependence.
lactobacillus-reuteri-SRC-002Randomized, double-blind, placebo-controlled trial
Sourceopen_in_newNaghibzadeh N, et al. Investigating the effect of quadruple therapy with Saccharomyces boulardii or Lactobacillus reuteri strain (DSMZ 17648) supplements on eradication of Helicobacter pylori and treatments adverse effects: a double-blind placebo-controlled randomized clinical trial. BMC Gastroenterol. 2022;22(1):107. doi:10.1186/s12876-022-02187-z. PMID:35255819
Population: 156 adults with H. pylori infection in 3 arms
Dose protocol: Quadruple therapy plus adjunct probiotic comparator arms
Key findings: No significant eradication advantage for L. reuteri arm
Notes: Mixed-arm design with limited power for moderate between-arm differences
Paper content
No significant eradication advantage for L. reuteri arm
lactobacillus-reuteri-SRC-003Randomized, double-blind, placebo-controlled trial
Sourceopen_in_newSung V, et al. Treating infant colic with the probiotic Lactobacillus reuteri: double blind, placebo controlled randomised trial. BMJ. 2014;348:g2107. doi:10.1136/bmj.g2107. PMID:24690625
Population: 167 breastfed/formula-fed infants with colic
Dose protocol: 1 × 10^8 CFU/day vs placebo for 1 month
Key findings: No benefit. Probiotic group had more fussing at primary endpoint
Notes: Good pragmatic design, mixed feeding profile
Paper content
No benefit; probiotic group had more fussing at primary endpoint
lactobacillus-reuteri-SRC-004Randomized, double-blind, placebo-controlled trial
Sourceopen_in_newChau K, et al. Probiotics for infantile colic: a randomized, double-blind, placebo-controlled trial investigating Lactobacillus reuteri DSM 17938. J Pediatr. 2015;166(1):74-78. doi:10.1016/j.jpeds.2014.09.020. PMID:25444531
Population: 52 breastfed infants with colic
Dose protocol: 1 × 10^8 CFU/day for 21 days
Key findings: Significant crying/fussing reduction and responder improvement
Notes: Small sample, selected population
Paper content
Significant crying/fussing reduction and responder improvement
lactobacillus-reuteri-SRC-005Meta-analysis of randomized controlled trials
Sourceopen_in_newXu M, et al. The Efficacy and Safety of the Probiotic Bacterium Lactobacillus reuteri DSM 17938 for Infantile Colic: A Meta-Analysis of Randomized Controlled Trials. PLoS One. 2015;10(10):e0141445. doi:10.1371/journal.pone.0141445. PMID:26509502
Population: 6 RCTs, 423 infants
Dose protocol: DSM 17938 in colic treatment trials
Key findings: Short-term crying-time improvement at 2-3 weeks, not sustained at 4 weeks
Notes: Trial heterogeneity and variable follow-up windows
Paper content
Short-term crying-time improvement at 2-3 weeks; not sustained at 4 weeks
lactobacillus-reuteri-SRC-006Narrative review
Sourceopen_in_newKullar R, et al. Lactobacillus Bacteremia and Probiotics: A Review. Microorganisms. 2023;11(4):896. doi:10.3390/microorganisms11040896. PMID:37110319
Population: Lactobacillus bacteremia literature with probiotic linkage analysis
Dose protocol: Not a dosing trial
Key findings: Rare but important invasive infection risk in high-risk populations
Notes: Narrative review design with disclosed conflicts
Paper content
Rare but clinically important invasive infection risk in high-risk patients
lactobacillus-reuteri-SRC-007Systematic review and meta-analysis of randomized controlled trials.
Sourceopen_in_newCheng Q, Ran Y, Mo X, et al. The efficacy and acceptability of Lactobacillus reuteri for the treatment of depression: A systematic review and meta-analysis. Gen Hosp Psychiatry. 2025;95:122-132. doi:10.1016/j.genhosppsych.2025.05.004. PMID:40339531.
Population: Adults with depression or depressive symptoms across various clinical settings.
Dose protocol: Systematic review and meta-analysis of 12 RCTs (n=1,258) testing L. reuteri-containing probiotics for depression
Key findings: Multi-strain formulations with L. reuteri showed moderate antidepressant effect (SMD -0.44). L. reuteri alone did not improve depression scores.
Notes: Important for limiting standalone mood claims. L. reuteri may contribute within multi-strain contexts but is not independently effective for depression.
Paper content
This systematic review and meta-analysis pooled 12 human RCTs (1,258 patients) evaluating L. reuteri-containing probiotics for depression. Multi-strain formulations containing L. reuteri showed a moderate effect (SMD -0.44) versus controls. However, L. reuteri alone did not significantly improve depressive symptoms. Subgroup analyses found the strongest benefits in women, patients under 60, and those with existing depressive symptoms. The study also included 9 animal experiments. The key finding for L. reuteri specifically is that its antidepressant potential appears dependent on co-administration with other probiotic strains rather than functioning as a standalone mood intervention. This reinforces the pattern that L. reuteri benefits are indication-specific and should not be overgeneralized.