Understanding Lactobacillus reuteri Strains
Lactobacillus reuteri is a species of bacteria that naturally resides in the mammalian gastrointestinal tract and has been part of human co-evolution for millions of years. As a probiotic, it has been widely studied for its beneficial effects on health, but it is critical to recognize that these effects are highly strain-specific. The two strains, L. reuteri DSM 17938 and L. reuteri ATCC PTA 6475, while belonging to the same species, have distinct functional properties and applications, making it important to understand their differences. These distinctions are primarily due to their unique genetic makeups and the specific compounds they produce.
The Profile of L. reuteri DSM 17938
L. reuteri DSM 17938, commercially known as Protectis, was originally isolated from the breast milk of a Peruvian mother. This strain is exceptionally well-documented in clinical research and is most famous for its use in infant health. Its primary mechanism of action involves the production of a potent, broad-spectrum antimicrobial compound called reuterin. This metabolite inhibits the growth of a wide range of harmful microorganisms, including pathogenic bacteria, yeasts, fungi, and protozoa.
Another key characteristic of DSM 17938 is its ability to modulate pain signaling. It has been shown in animal models to reduce the signaling of TRPV1 pain receptors, which may be part of the mechanism for its effectiveness in reducing crying time in infants with colic. In addition to its impact on infantile colic, studies have demonstrated its effectiveness in addressing other functional gastrointestinal disorders, such as constipation and acute gastroenteritis. The strain helps to regulate gut motility and restore a balanced gut microbiota composition.
The Profile of L. reuteri ATCC PTA 6475
In contrast, L. reuteri ATCC PTA 6475 is an anti-inflammatory strain, isolated from the breast milk of a Finnish woman. Its anti-inflammatory properties are linked to its ability to produce the biogenic amine histamine from the dietary amino acid L-histidine. This histamine activates the H2 receptors on immune cells, suppressing the production of pro-inflammatory cytokines like TNF-α.
Beyond its powerful anti-inflammatory effects, ATCC PTA 6475 has demonstrated a notable influence on the gut-brain axis, supporting neurological signaling pathways. In mouse models, this strain has been shown to induce oxytocin production, which has implications for social behavior and mood regulation. Its potent anti-inflammatory action also makes it a valuable candidate for managing inflammatory conditions like Irritable Bowel Syndrome (IBS). Research shows that it can help decrease inflammatory markers, such as fecal calprotectin, in adults with IBS.
Comparison of L. reuteri 17938 and 6475
| Feature | L. reuteri DSM 17938 | L. reuteri ATCC PTA 6475 |
|---|---|---|
| Primary Function | Antimicrobial, gut motility support | Anti-inflammatory, immune regulation |
| Key Metabolite | Reuterin | Histamine |
| Mechanism of Action | Inhibits pathogenic microbes, modulates visceral pain receptors | Suppresses pro-inflammatory cytokines via H2 receptor activation |
| Targeted Conditions | Infant colic, acute gastroenteritis, constipation | Inflammatory conditions (e.g., IBS), gut-brain axis disorders |
| Gut-Brain Effect | Pain signaling modulation | Induces oxytocin, supports gut-brain communication |
| Origin | Breast milk of a Peruvian mother | Breast milk of a Finnish woman |
| Clinical Focus | Pediatric gastroenterology (colic, diarrhea) | Adult inflammatory and functional GI disorders (IBS) |
Synergistic Effects of Combining Strains
Interestingly, recent clinical trials have explored the combination of L. reuteri DSM 17938 and ATCC PTA 6475. The hypothesis is that their different modes of action can produce synergistic or complementary effects. A randomized, double-blind, placebo-controlled trial involving adults with moderate-to-severe IBS found that a combination of these two strains effectively reduced IBS symptoms and improved stool consistency. This suggests that leveraging the strengths of each strain—the anti-pathogenic action of 17938 and the anti-inflammatory action of 6475—can lead to broader and more effective therapeutic outcomes for complex gastrointestinal issues. The dual approach addresses both microbial imbalance and underlying inflammation, offering a comprehensive solution.
Conclusion
Ultimately, the choice between L. reuteri 17938 and 6475 depends on the specific health concern being addressed. If the goal is to manage conditions associated with microbial imbalance or visceral pain, such as infant colic or infectious diarrhea, the well-researched DSM 17938 is the appropriate choice, given its potent reuterin production. On the other hand, for inflammatory gastrointestinal conditions like IBS and potentially for modulating the gut-brain axis, ATCC PTA 6475 offers a targeted approach through its histamine-based anti-inflammatory effects. Recognizing that not all probiotics are created equal, and that their benefits are strain-specific, allows for more informed and effective supplementation.
For additional in-depth information on the specific mechanisms of Lactobacillus reuteri strains, consult peer-reviewed research available on the National Institutes of Health website at https://pubmed.ncbi.nlm.nih.gov/.
Frequently Asked Questions
What is the primary difference in function between L. reuteri 17938 and 6475? L. reuteri 17938 is primarily known for its antimicrobial properties due to the production of reuterin, while L. reuteri 6475 is known for its potent anti-inflammatory effects derived from histamine production.
Is L. reuteri 17938 only for infants? No, while it is most famously studied and used for infant colic, L. reuteri 17938 also has applications in adults for managing functional gastrointestinal disorders like constipation and diarrhea.
How does L. reuteri 6475 affect the immune system? L. reuteri 6475 produces histamine, which activates H2 receptors on immune cells to suppress the production of pro-inflammatory cytokines like TNF-α, thereby exerting an anti-inflammatory effect.
Can L. reuteri 17938 and 6475 be taken together? Yes, studies suggest that combining these strains can produce complementary effects, addressing both antimicrobial and anti-inflammatory pathways for broader benefits in conditions like IBS.
Which strain is better for gut-brain axis support? Both strains influence the gut-brain axis but through different mechanisms. ATCC PTA 6475 specifically affects pathways by inducing oxytocin and regulating histamine, whereas DSM 17938 modulates visceral pain signaling. The best choice depends on the specific aspect of the gut-brain connection you wish to support.
Is the source of the strain important? Yes, the origin of the strain contributes to its specific properties. DSM 17938 originated from Peruvian breast milk, and ATCC PTA 6475 from Finnish breast milk, and these distinct evolutionary paths have resulted in their unique functional differences.
Is one strain more effective than the other? No, one strain is not inherently more effective than the other; their effectiveness is specific to the condition they are being used for. Choosing the right strain depends on whether you need targeted antimicrobial action (17938) or anti-inflammatory support (6475).
