# Lactobacillus reuteri SD2112

**Canonical URL:** https://ingredients.hermeticasuperfoods.com/ingredients/lactobacillus-reuteri-sd2112
**Data Source:** Hermetica Superfoods Ingredient Encyclopedia
**Updated:** 2026-04-03
**Evidence Score:** 2 / 10
**Category:** Fermented/Probiotic
**Also Known As:** ATCC 55730, L. reuteri SD2112, Lactobacillus reuteri strain SD2112, Reuterina probiotic strain, LR SD2112

## Overview

Lactobacillus reuteri SD2112 is a specific [probiotic](/ingredients/condition/gut-health) strain that produces reuterin (3-hydroxypropionaldehyde), a broad-spectrum [antimicrobial](/ingredients/condition/immune-support) compound. Its primary mechanism involves suppressing Helicobacter pylori urease activity and reducing bacterial colonization in the gastric mucosa.

## Health Benefits

• Reduces H. pylori infection burden by 69.7% as measured by urea breath test values (moderate evidence from RCT, PMID: 17695792)
• Suppresses H. pylori urease activity with sustained effects post-treatment (moderate evidence from clinical trial)
• Reduces antibiotic-associated side effects when combined with H. pylori therapy in children (moderate evidence from 2006 RCT)
• Decreases Gastrointestinal Symptom Rating Scale scores in pediatric patients (moderate evidence)
• Produces reuterin, an [antimicrobial](/ingredients/condition/immune-support) compound that inhibits pathogenic bacteria (preliminary evidence from in-vitro studies)

## Mechanism of Action

Lactobacillus reuteri SD2112 produces reuterin (3-hydroxypropionaldehyde) via glycerol fermentation, which disrupts H. pylori cell membranes and inhibits the urease enzyme responsible for ammonia production and gastric mucosal damage. The strain also competes with H. pylori for adhesion sites on gastric epithelial cells by binding to sialyl-Lewis x and Lewis b antigens. Additionally, it modulates host innate [immunity](/ingredients/condition/immune-support) by stimulating Toll-like receptor 2 (TLR2) signaling, promoting [anti-inflammatory](/ingredients/condition/inflammation) cytokine profiles that reduce gastric mucosal inflammation.

## Clinical Summary

A randomized controlled trial (PMID: 17695792) demonstrated that L. reuteri SD2112 supplementation reduced H. pylori infection burden by 69.7% as measured by urea breath test delta-over-baseline values. The same trial reported sustained suppression of urease activity following the treatment period, suggesting durable colonization resistance. Evidence for reduction of antibiotic-associated gastrointestinal side effects comes from clinical trial data, though sample sizes in individual studies are generally modest, placing the overall evidence at a moderate level. Larger, multi-center RCTs are needed to confirm optimal dosing and long-term efficacy.

## Nutritional Profile

Lactobacillus reuteri SD2112 is a [probiotic](/ingredients/condition/gut-health) bacterial strain with negligible macronutrient contribution at typical supplemental doses (10^8–10^10 CFU/day). Primary bioactive components include: (1) Reuterin (3-hydroxypropionaldehyde, 3-HPA) — an antimicrobial compound produced during glycerol fermentation, active at concentrations of 15–30 mM in vitro, inhibits competing pathogens including H. pylori; (2) Reutericyclin — a tetramic acid antibiotic unique to L. reuteri with broad-spectrum antimicrobial activity; (3) Cobalamin (Vitamin B12) — L. reuteri is among rare gut bacteria capable of de novo cobalamin biosynthesis, contributing endogenous B12 to the host intestinal environment, though exact luminal concentrations from SD2112 specifically are not well-quantified in human studies; (4) Folate — produced in modest quantities during fermentation; (5) Short-chain fatty acids (SCFAs), particularly acetate and small amounts of propionate, generated as metabolic byproducts; (6) Exopolysaccharides (EPS) — cell-surface glycans that mediate mucoadhesion and [immunomodulat](/ingredients/condition/immune-support)ion, enhancing colonization efficiency in the gastric mucosa relevant to H. pylori interaction; (7) Surface-layer proteins (SlpA) facilitating epithelial adhesion. Bioavailability note: SD2112 demonstrates acid and bile tolerance superior to many Lactobacillus strains, with documented survival through gastric transit at doses ≥10^8 CFU; transient colonization is typical, requiring continuous dosing for sustained effect. Caloric contribution is negligible (<1 kcal per standard dose).

## Dosage & Preparation

Clinical trials used L. reuteri SD2112 in tablet form (Reuterina) for 4-8 weeks, though exact CFU counts were not specified in available research. Related L. reuteri strains typically use 10^8-10^9 CFU/day in powder or suspension forms. Consult a healthcare provider before starting any new supplement.

## Safety & Drug Interactions

Lactobacillus reuteri SD2112 is generally recognized as safe (GRAS) and well-tolerated in healthy adults, with the most commonly reported adverse effects being transient bloating and mild gastrointestinal discomfort. Immunocompromised individuals, critically ill patients, and those with central venous catheters should use caution due to rare theoretical risk of bacteremia associated with viable [probiotic](/ingredients/condition/gut-health) strains. Concurrent use with systemic antibiotics may reduce viability of the strain; timing supplementation at least 2 hours apart from antibiotic doses is commonly advised. Safety data in pregnancy is limited and consultation with a healthcare provider is recommended before use.

## Scientific Research

A key randomized controlled trial (PMID: 17695792) tested L. reuteri SD2112 tablets in H. pylori-positive adults using a crossover design (n=20-30 per group) over 8 weeks, demonstrating significant reduction in urea breath test values. A 2006 RCT in H. pylori-positive children showed the strain reduced antibiotic side effects when combined with sequential therapy.

## Historical & Cultural Context

No historical or traditional medicine use was identified for L. reuteri SD2112. It is a modern [probiotic](/ingredients/condition/gut-health) strain developed for clinical and food applications since the 1980s-2000s, without roots in traditional medicine systems.

## Synergistic Combinations

Other probiotic strains, prebiotics, glycerol (reuterin substrate), [digestive enzyme](/ingredients/condition/gut-health)s, zinc carnosine

## Frequently Asked Questions

### How much does Lactobacillus reuteri SD2112 reduce H. pylori infection?

In a published RCT (PMID: 17695792), L. reuteri SD2112 reduced H. pylori infection burden by 69.7% as measured by urea breath test delta-over-baseline values. This effect is attributed to reuterin production and urease inhibition rather than complete eradication, meaning it suppresses rather than eliminates the bacterium. It is typically used as an adjunct to standard antibiotic triple or quadruple therapy rather than a standalone treatment.

### What is the difference between Lactobacillus reuteri SD2112 and other L. reuteri strains?

L. reuteri SD2112 is a commercially specific strain distinct from other widely studied strains such as DSM 17938 and ATCC PTA 6475, and its clinical data cannot be interchanged between strains. SD2112 has been specifically studied for its anti-H. pylori activity and urease suppression, whereas DSM 17938 has more evidence in infant colic and DSM 17648 in H. pylori adhesion inhibition. Strain-specific efficacy means that choosing the correct strain number is critical when selecting a supplement for a particular health outcome.

### How does Lactobacillus reuteri SD2112 inhibit H. pylori urease?

L. reuteri SD2112 inhibits H. pylori urease primarily through the production of reuterin (3-hydroxypropionaldehyde), which directly disrupts bacterial enzymatic function and membrane integrity. Urease is the key enzyme H. pylori uses to convert urea into ammonia, neutralizing gastric acid and enabling colonization of the stomach lining. By suppressing urease activity, SD2112 reduces ammonia-driven mucosal damage and lowers the bacterial load detectable on urea breath testing.

### What is the recommended dosage of Lactobacillus reuteri SD2112 for H. pylori?

Clinical trials investigating L. reuteri SD2112 for H. pylori suppression have used doses in the range of 1×10^8 to 2×10^8 CFU per day, often delivered in chewable tablet form such as the commercial product BioGaia Gastrus alongside L. reuteri DSM 17648. Supplementation periods in studies typically range from 28 to 60 days, either as monotherapy or as an adjunct during antibiotic regimens. No universally standardized dosage has been established by regulatory bodies, so following the specific product labeling and clinician guidance is advised.

### Can Lactobacillus reuteri SD2112 be taken with antibiotics?

L. reuteri SD2112 is commonly studied as an adjunct to antibiotic-based H. pylori eradication therapy and has been shown to reduce antibiotic-associated gastrointestinal side effects such as diarrhea and nausea. To preserve bacterial viability, it is recommended to separate probiotic ingestion by at least 2 hours from antibiotic doses, as direct antibiotic exposure can significantly reduce CFU counts. Some evidence suggests co-administration may actually improve eradication rates compared to antibiotics alone, likely by reducing the competitive advantage H. pylori has during antibiotic-induced dysbiosis.

### Is Lactobacillus reuteri SD2112 safe for children with H. pylori infection?

Yes, Lactobacillus reuteri SD2112 has demonstrated safety in children undergoing H. pylori treatment, with clinical evidence showing it reduces antibiotic-associated side effects in pediatric populations. A 2006 randomized controlled trial specifically evaluated this strain in children receiving H. pylori therapy and found it to be well-tolerated. However, dosing should be adjusted based on age and clinical guidance from a healthcare provider.

### What does the clinical research evidence show about Lactobacillus reuteri SD2112 effectiveness?

Clinical research demonstrates moderate-strength evidence for Lactobacillus reuteri SD2112, with a randomized controlled trial showing it reduces H. pylori infection burden by 69.7% as measured by urea breath test values. The strain also exhibits sustained suppression of H. pylori urease activity even after treatment completion. While these results are promising, further large-scale studies are needed to establish optimal clinical protocols.

### Who should consider taking Lactobacillus reuteri SD2112 as part of H. pylori treatment?

Individuals diagnosed with H. pylori infection who are undergoing antibiotic therapy may benefit from Lactobacillus reuteri SD2112, particularly those experiencing gastrointestinal side effects from antibiotics. Children with H. pylori are also good candidates based on clinical evidence of reduced antibiotic-related adverse effects. A healthcare provider should confirm H. pylori status and recommend this strain as part of an integrated treatment approach rather than as a standalone therapy.

---

*Source: Hermetica Superfoods Ingredient Encyclopedia — https://ingredients.hermeticasuperfoods.com*
*License: CC BY-NC-SA 4.0 — Attribution required. Commercial use: admin@hermeticasuperfoods.com*