Home Ingredients Limosilactobacillus reuteri DSM 17938 (BioGaia Protectis®)
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Limosilactobacillus reuteri DSM 17938 (BioGaia Protectis®)

Limosilactobacillus reuteri DSM 17938 (formerly Lactobacillus reuteri DSM 17938)
Evidence Level
Strong
3 Clinical Trials
7 Documented Benefits
4/5 Evidence Score

Limosilactobacillus reuteri DSM 17938 is a specific probiotic strain marketed as BioGaia Protectis® — one of the most clinically studied strains for infant and pediatric gastrointestinal conditions. It has the strongest evidence base for reducing infant colic crying time in breastfed infants, with multiple randomized trials and meta-analyses showing roughly 50% reductions in daily crying. Also has evidence for functional abdominal pain in children, antibiotic-associated diarrhea prevention, and Helicobacter pylori adjunct support. In adults, evidence extends to constipation and certain GI conditions but is less robust than the pediatric data. The honest framing: this is one of the better-evidenced probiotic strains for specific pediatric indications — particularly breastfed infant colic — and a reasonable choice for adult digestive support, though the adult evidence is more variable.

Studied Dose Infants: 100 million CFU (1x10^8)/day as drops. Children: 100-400 million CFU/day. Adults: 100 million to 1 billion CFU/day.
Active Compound Limosilactobacillus reuteri DSM 17938 (formerly Lactobacillus reuteri DSM 17938); daughter strain of L. reuteri ATCC 55730 with antibiotic-resistance genes removed.

Benefits

Infant colic crying time reduction

Multiple randomized trials in breastfed infants show that L. reuteri DSM 17938 reduces daily crying time roughly 50% versus placebo over 21-28 days. The strongest single-supplement evidence for infant colic. Effects are smaller and less consistent in formula-fed infants.

Supported by Trial 1, Trial 3

Functional abdominal pain in children

Randomized trials in children with functional abdominal pain show reduced pain intensity and frequency over 4 weeks of supplementation. Effect sizes are moderate but clinically meaningful for a condition with few good interventions.

Supported by Trial 2

Antibiotic-associated diarrhea prevention

L. reuteri DSM 17938 reduces the risk of antibiotic-associated diarrhea in adults and children. Effect sizes are modest but consistent across trials. Take 2-3 hours apart from the antibiotic dose to preserve probiotic viability.

Supported by Trial 1

H. pylori eradication adjunct

Used alongside standard triple therapy for H. pylori infection, L. reuteri DSM 17938 reduces side effects of antibiotic therapy and may modestly improve eradication rates. Adjunct support rather than standalone treatment.

Supported by Trial 1

Functional constipation in children

Some randomized trials in pediatric functional constipation show improved stool frequency with L. reuteri DSM 17938 over weeks of use. Evidence is mixed across trials; not all studies have shown benefit.

Supported by Trial 1, Trial 2

Adult digestive comfort and bloating

Emerging evidence in adults with mild digestive symptoms shows reductions in bloating and improved comfort over 4-8 weeks. Adult evidence is less robust than pediatric, but the safety profile makes it a reasonable trial.

Supported by Trial 1, Trial 2

Oral health support (separate strain product)

Specific Lactobacillus reuteri strains in lozenges (different products from BioGaia Protectis®) have evidence for gingivitis and periodontal health. Different formulation; oral health products use different strains and delivery formats.

Supported by Trial 1

Mechanism of action

1

Reuterin antimicrobial production (distinguishing)

Reuterin (3-hydroxypropionaldehyde) is a broad-spectrum antimicrobial active against bacteria, fungi, and protozoa. Produced by L. reuteri species — the distinguishing mechanism among Lactobacillus species.

2

Gut motility modulation

DSM 17938 modulates gut motility — increasing motility in constipation and reducing visceral effects in colic. Mechanism shared across the constipation and colic indications.

3

TLR2 immunomodulation

Toll-like receptor 2 (TLR2) immunomodulation supports the immune and anti-inflammatory effects.

4

Microbiota normalization in colic

Colicky infants have altered baseline microbiota; DSM 17938 contributes to microbiota normalization. Mechanism for the colic improvement beyond direct visceral effects.

5

Anti-inflammatory cytokine modulation

Cytokine modulation contributes to the broader anti-inflammatory effects.

6

Strain-specific safety engineering

DSM 17938 is the daughter strain of parent ATCC 55730 — antibiotic-resistance genes were genetically removed for safety. Reflects rigorous strain-specific safety engineering for an infant-exposed product.

Clinical trials

1
L. reuteri DSM 17938 Infantile Colic meta-analysis

Clinical evidence on Limosilactobacillus reuteri DSM 17938 (BioGaia Protectis®) for the indications and outcomes described.

Clinical population described in trial publication.

Xu S et al. 2015 (, PLOS one 10(10):e0141445). Pooled analysis of 6 clinical trials in 423 infants. Treatment effectiveness 2 weeks RR 2.84 (95% CI 1.24-6.50, p=0.014); 3 weeks RR 2.33 (95% CI 1.38-3.93, p=0.002). Crying time WMD -42.89 min/day at 2 weeks; -45.83 min/day at 3 weeks. No weight/length/head circumference influence. No serious adverse events.

2
PMC5758237 — Network meta-analysis of 32 Clinical Trial Infantile Colic (n=2,242)

Network pooled analysis of 32 clinical trials in 2,242 patients.

2,242 patients

Network pooled analysis of 32 clinical trials in 2,242 patients. Comparative superiority over diet, acupuncture, and other interventions for infantile colic.

3
Foundational Breastfed Colic Clinical Trial

Foundational clinical trial in 50 exclusively breastfed colicky infants.

Clinical population described in trial publication.

Foundational clinical trial in 50 exclusively breastfed colicky infants. 1×10⁸ CFU/day × 21 days. Established the standard 5 drops/day dose.

Side effects and drug interactions

Common Potential side effects

Generally extremely well-tolerated; extensive infant safety record.
NO weight, length, head circumference influence (Xu 2015 meta-analysis).
NO serious adverse events documented across multiple meta-analyses.
Mild GI upset (rare in infants).
Pregnancy/lactation: safe — frequently used during breastfeeding for both maternal and infant applications.
Long-term safety: extensive multi-meta-analytic evidence supportive.
Industry-sponsorship (BioGaia AB) — important context.

Important Drug interactions

Antibiotics: take 2-3 hours apart from L. reuteri DSM 17938 dose.
Most medications: well-tolerated combination profile.
Immunosuppressants: caution (applies to all probiotics; especially in infants).
Anticoagulants: no interactions documented.
Other probiotics: compatible.
Helicobacter pylori eradication therapy: enhanced outcomes per Francavilla 2008+ trials.

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Frequently asked questions about Limosilactobacillus reuteri DSM 17938 (BioGaia Protectis®)

What is Limosilactobacillus reuteri DSM 17938?

Limosilactobacillus reuteri DSM 17938 is a specific probiotic strain marketed as BioGaia Protectis® — one of the most clinically studied strains for infant and pediatric gastrointestinal conditions.

What is Limosilactobacillus reuteri DSM 17938 used for?

Limosilactobacillus reuteri DSM 17938 is researched primarily for Gut Health and Immune Support. Multiple randomized trials in breastfed infants show that L. reuteri DSM 17938 reduces daily crying time roughly 50% versus placebo over 21-28 days. The strongest single-supplement evidence for infant colic.

What is the recommended dosage of Limosilactobacillus reuteri DSM 17938?

The clinically studied dose is Infants: 100 million CFU (1x10^8)/day as drops. Children: 100-400 million CFU/day. Adults: 100 million to 1 billion CFU/day. Always follow the product label and check with a healthcare provider for personal advice.

Is Limosilactobacillus reuteri DSM 17938 safe, and does it have side effects?

For most healthy adults, Limosilactobacillus reuteri DSM 17938 is well tolerated at studied doses. Reported effects can include: Generally extremely well-tolerated; extensive infant safety record. NO weight, length, head circumference influence (Xu 2015 meta-analysis). It may also interact with some medications. Limosilactobacillus reuteri DSM 17938 is not right for everyone, so check with a healthcare provider first if you are pregnant or breastfeeding, have a medical condition, or take prescription medication.

Does Limosilactobacillus reuteri DSM 17938 interact with any medications?

Possible interactions include: Antibiotics: take 2-3 hours apart from L. reuteri DSM 17938 dose. Most medications: well-tolerated combination profile. If you take prescription medication, check with a pharmacist or doctor before using it.

How strong is the scientific evidence for Limosilactobacillus reuteri DSM 17938?

NutraSmarts rates the evidence for Limosilactobacillus reuteri DSM 17938 as Strong (4 out of 5). It is backed by 3 clinical trials and 4 cited references summarized on this page. A higher rating reflects more, larger, and better-designed human studies.

References(4 citations)

Evidence ratings on NutraSmarts are based on the totality of human clinical research, with emphasis on randomized controlled trials, meta-analyses, and systematic reviews. The references below directly support claims made throughout this page.

  1. Savino F, Cordisco L, Tarasco V, Palumeri E, Calabrese R, Oggero R, et al. Lactobacillus reuteri DSM 17938 in infantile colic: a randomized, double-blind, placebo-controlled trial. Pediatrics. 2010;126(3):e526-33. doi: 10.1542/peds.2010-0433.PubMedUsed to support: Key strain-specific RCT showing L. reuteri DSM 17938 reduced daily crying time in colicky infants. Note: participants were exclusively/predominantly breastfed; the benefit is most consistent in breastfed infants.
  2. Savino F, Garro M, Montanari P, Galliano I, Bergallo M Crying Time and ROR-gamma/FOXP3 Expression in Lactobacillus reuteri DSM17938-Treated Infants with Colic: A Randomized Trial. J Pediatr. 2018;192:171-177.e1. doi: 10.1016/j.jpeds.2017.08.062.PubMedUsed to support: Later DSM 17938 colic RCT confirming reduced crying time alongside immune/regulatory T-cell changes. Reinforces the colic benefit; still a small, single-center trial.
  3. Sung V, D'Amico F, Cabana MD, Chau K, Koren G, Savino F, et al. Lactobacillus reuteri to Treat Infant Colic: A Meta-analysis. Pediatrics. 2018;141(1):e20171811. doi: 10.1542/peds.2017-1811.PubMedUsed to support: Individual-participant-data meta-analysis of DSM 17938 colic trials: effective in breastfed infants but evidence inconsistent/inconclusive in formula-fed infants. The honest population-specific caveat.
  4. Indrio F, Di Mauro A, Riezzo G, Civardi E, Intini C, Corvaglia L, et al. Prophylactic use of a probiotic in the prevention of colic, regurgitation, and functional constipation: a randomized clinical trial. JAMA Pediatr. 2014;168(3):228-33. doi: 10.1001/jamapediatrics.2013.4367.PubMedUsed to support: RCT showing prophylactic L. reuteri DSM 17938 reduced colic, regurgitation, and constipation in the first months of life. Supports the regurgitation/constipation uses; a prevention (not treatment) trial.