Lactobacillus reuteri Dosing for H. pylori Eradication
Lactobacillus reuteri DSM 17938 should be administered at a dose of 1-2 × 10^8 CFU twice daily as an adjunct to standard H. pylori eradication therapy for the duration of antibiotic treatment (typically 10-14 days), with consideration for extending probiotic use for an additional 2-3 weeks after antibiotics to support microbiome recovery. 1
Evidence-Based Dosing Recommendations
Standard Dosing Protocol
L. reuteri DSM 17938 at 1-2 × 10^8 CFU twice daily is the most commonly studied and recommended dose for H. pylori adjunctive therapy 1, 2
Duration should match the antibiotic regimen (10-14 days minimum), with the strongest evidence supporting 14-day courses 3, 2
Extended probiotic administration for 27-30 days total (continuing 2-3 weeks beyond antibiotic completion) may provide additional benefit for microbiome recovery, though eradication rates are similar 4
Clinical Efficacy Data
The addition of L. reuteri to standard H. pylori therapy demonstrates:
Improved eradication rates by approximately 7-10% in intention-to-treat analysis (80.0% vs 72.6%, RR: 1.10, NNT = 14) 2
Significant reduction in adverse events (RR: 0.72,95% CI: 0.67-0.78), particularly diarrhea and nausea 3, 2
Greater improvement in gastrointestinal symptom scores (mean difference: -2.43,95% CI: -4.56 to -0.29) 2
Practical Implementation
Timing and Administration
Take L. reuteri with meals to optimize survival and colonization 4
Begin probiotic supplementation simultaneously with antibiotic therapy, not before or after 3, 2
Continue for full antibiotic course at minimum, with option to extend 2-3 weeks post-antibiotics 4
Specific Clinical Scenarios
For second-line levofloxacin-based therapy:
- L. reuteri 10^8 CFU twice daily for 14 days significantly improved eradication from 62% to 80% (P < 0.05) 3
For bismuth quadruple therapy:
- L. reuteri can be used as an alternative to bismuth in patients with contraindications, though bismuth remains more effective (95.5% vs 85.7% eradication by per-protocol analysis) 4
Important Caveats and Limitations
Realistic Expectations
L. reuteri alone with PPI (without antibiotics) achieves only 12.5% eradication and is not clinically useful as monotherapy 5
The benefit is additive, not synergistic - probiotics add approximately 12-14% to whatever baseline eradication rate the antibiotic regimen achieves 1, 5
Probiotics can only reliably achieve ≥90% eradication when added to regimens already achieving ~80% cure rates 5
Strain Specificity Matters
Only L. reuteri DSM 17938 has consistent evidence for H. pylori eradication 1, 2
Single-strain Lactobacillus preparations show superior benefit (17% improvement) compared to multi-strain probiotics (2.8% improvement) 1
Other probiotic strains and formulations have inconsistent evidence and should not be substituted 1
Guideline Perspectives Show Divergence
ESPGHAN (European pediatric guidelines) recommend L. reuteri DSM 17938 for adjunct treatment in acute gastroenteritis and support its use in H. pylori therapy 1
Toronto and ACG guidelines discourage routine probiotic use due to concerns about trial quality and inconsistent formulations 1
European guidelines suggest case-by-case consideration for fragile patients or those with poor antibiotic tolerance 1
Microbiome Impact
L. reuteri does not prevent antibiotic-induced dysbiosis - both bismuth and L. reuteri groups showed similar reductions in alpha diversity and beneficial bacterial genera during treatment 4
Microbiome recovery occurs naturally 30-40 days post-treatment regardless of probiotic supplementation 4
The primary benefit is symptom reduction and modest eradication improvement, not microbiome preservation 2, 4
Clinical Decision Algorithm
Use L. reuteri DSM 17938 (1-2 × 10^8 CFU twice daily) when:
- Patient has history of antibiotic intolerance or GI side effects 3, 2
- Using suboptimal first-line regimens with expected eradication <80% 5
- Patient is fragile, elderly, or has multiple comorbidities 1
- Bismuth is contraindicated and alternative adjunct is needed 4
Do not rely on L. reuteri when: