What is Lactobacillus reuteri?
Lactobacillus reuteri is a species of probiotic bacteria that naturally colonizes the gastrointestinal (GI) tract of humans and many other vertebrates. Historically present in high numbers within the human gut, its population has seen a decline due to modern lifestyles, changes in diet, and increased use of antibiotics. This versatile probiotic is known for producing antimicrobial substances, most notably reuterin, which helps it compete with and suppress the growth of harmful pathogens. It is also adept at surviving in diverse environments, including the low pH of the stomach, and can colonize various mucosal surfaces, including the gut and mouth.
Digestive and Gut Health Benefits
L. reuteri is perhaps best known for its positive impact on digestive health. It works by reinforcing the gut barrier, balancing the intestinal flora, and producing short-chain fatty acids (SCFAs) that support gut function. Clinical studies have shown its efficacy in managing several common GI issues, including:
- Diarrhea: Supplementation with L. reuteri has been shown to reduce the duration of acute watery diarrhea in children. It competes with pathogenic bacteria like Escherichia coli and Salmonella, helping to restore microbial balance.
- Constipation: In both children and adults, certain strains of L. reuteri, such as DSM 17938, have been shown to improve stool frequency and gut motility.
- Infantile Colic: For exclusively breastfed infants, the administration of L. reuteri DSM 17938 has been shown to significantly reduce daily crying and fussing time. Its anti-inflammatory properties may also play a role in alleviating colic symptoms.
- Helicobacter pylori Infection: When used in combination with standard drug therapy for H. pylori, L. reuteri can help reduce the antibiotic-related side effects, such as abdominal pain and taste disturbances, thereby improving treatment compliance.
Benefits for Oral Health
The presence of L. reuteri extends to the oral cavity, where it can provide significant benefits for dental and gum health. It combats harmful bacteria that contribute to plaque formation, tooth decay, and gum disease through the production of antimicrobial compounds. Specific applications include:
- Gingivitis and Periodontitis: Regular intake of lozenges containing L. reuteri has been shown to reduce inflammation, bleeding on probing, and periodontal pocket depths.
- Dental Caries: L. reuteri helps fight cariogenic bacteria like Streptococcus mutans, which are responsible for acid production that erodes tooth enamel.
- Oral Candidiasis: This probiotic has demonstrated antifungal properties against various Candida species, helping to reduce the fungal load in the oral environment.
Immunomodulatory Effects and Systemic Benefits
Beyond the gut and mouth, L. reuteri has broader, systemic impacts through its ability to modulate the immune system. It influences immune cells and cytokines, promoting an anti-inflammatory response.
- Immune System Support: By promoting anti-inflammatory cytokines like IL-10 and decreasing pro-inflammatory ones, L. reuteri helps regulate the immune response and reduce chronic inflammation. This mechanism is crucial for mitigating the inflammation associated with conditions like inflammatory bowel disease (IBD).
- Skin Health: The 'gut-skin axis' theory suggests a link between gut health and skin conditions. Studies indicate that L. reuteri may improve skin health by reducing inflammation and supporting a balanced skin microbiome, potentially helping with conditions like acne.
- Bone Health: Some research suggests that L. reuteri may help maintain bone health by influencing the immune system, which plays a role in bone density regulation.
- Neurodevelopmental Conditions: Promising preclinical research in animal models has suggested that L. reuteri may help address social deficits related to autism spectrum disorder (ASD) by influencing the gut-brain axis, though human studies are needed.
A Comparative Look at Probiotics
While many probiotics offer health benefits, L. reuteri stands out for its specific mechanisms and documented effects. The following table highlights key differences between L. reuteri and another well-researched strain, Lactobacillus rhamnosus GG (LGG).
| Feature | L. reuteri (e.g., DSM 17938) | Lactobacillus rhamnosus GG (LGG) |
|---|---|---|
| Mechanism of Action | Produces antimicrobial reuterin and modulates inflammation via cytokines. | Modulates immune response and supports gut barrier function. |
| Key Benefits | Effective for infant colic, H. pylori side effects, and oral health. | Well-researched for preventing and treating diarrhea, especially antibiotic-associated diarrhea. |
| Strain Specificity | Effects are highly strain-specific; efficacy varies based on the specific strain used. | LGG is a highly researched strain with a wide range of documented benefits. |
| Gut Colonization | Historically indigenous to the human GI tract, can colonize various mucosal surfaces. | Can survive the harsh GI environment and colonize the gut for a transient period. |
How to Get Your L. reuteri Fix
L. reuteri is available in various probiotic products, including capsules, chewable tablets, and liquids. The effectiveness can depend on the specific strain and the product formulation. For example, some products are designed with capsules that protect the bacteria from stomach acid. High-quality, reputable brands often specify the strain used, such as DSM 17938 or RC-14, which have been extensively studied. It is advisable to take probiotics with or without food, as directed by the product label. If taking antibiotics, separate the doses by at least 2-3 hours to ensure the probiotics' efficacy. Some enthusiasts also create their own L. reuteri-fermented dairy, like yogurt, using a specific culture and a longer fermentation time to increase the bacterial count.
Conclusion
In summary, L. reuteri is a multifaceted probiotic with scientifically supported benefits across numerous aspects of human health. Its ability to produce antimicrobial compounds and modulate the immune system makes it a powerful ally for digestive, oral, and systemic wellness. While its efficacy is often strain-specific, particularly well-researched strains like DSM 17938 and RC-14 offer proven results for conditions such as infant colic, periodontitis, and H. pylori side effects. As research continues to uncover new applications, such as its potential role in systemic inflammatory diseases and neurodevelopmental conditions, L. reuteri remains a highly promising and versatile supplement for supporting overall health and well-being.
Potential Considerations
While generally safe, some individuals may experience mild side effects like gas or bloating when first starting L. reuteri. It is important to consult a healthcare provider, especially for immunocompromised individuals, pregnant or breastfeeding women, or those with underlying health conditions, to ensure its suitability.
Authority Outbound Link: For more in-depth scientific research on L. reuteri and its mechanisms, consult publications from the National Center for Biotechnology Information (NCBI) on PubMed, such as this overview.
