What is Lactobacillus salivarius?
Lactobacillus salivarius, officially reclassified as Ligilactobacillus salivarius, is a 'good' bacteria naturally found in the human mouth and intestines. Its probiotic properties, such as producing antimicrobial substances and influencing the gut microbiota, have been a focus of scientific study, revealing its ability to influence the immune system. It has also received 'generally recognized as safe' (GRAS) status from the FDA.
How Lactobacillus salivarius Modulates Immunity
L. salivarius modulates immunity by balancing inflammatory responses and enhancing protective mechanisms. The specific effects depend on the strain. Key mechanisms include:
- Cytokine Regulation: Different strains influence the production of immune signaling molecules called cytokines. Some strains, like LS01 and UCC118, increase the anti-inflammatory cytokine IL-10. Other strains can increase pro-inflammatory cytokines like IL-12 and IFN-γ to fight pathogens.
- Mucosal Barrier Enhancement: L. salivarius can strengthen the mucosal barrier in the respiratory, oral, and intestinal tracts, which helps prevent pathogens from entering tissues.
- Macrophage and T-Cell Activation: This probiotic can activate immune cells such as macrophages and T-cells, promoting the clearance of pathogens.
- Microbiome Modulation: L. salivarius contributes to a healthy microbial balance in the gut by producing beneficial substances like bacteriocins and short-chain fatty acids (SCFAs). A balanced microbiome is essential for immune system development and function.
Research Findings on L. salivarius and Immunity
Studies in various models have explored the immune effects of L. salivarius:
- Oral and Respiratory Health: Strains isolated from the mouth, like AR809, adhere to cells, inhibit pathogens, and modulate immunity. Studies in chickens showed reduced inflammation and restored mucosal barriers during infection.
- Gastrointestinal Health: The strain UCC118 reduced inflammation in a colitis model by increasing IL-10 and restoring gut microbiome balance. In piglets, L. salivarius B1 helped mature the intestinal immune system.
- Anti-inflammatory Effects: Components of L. salivarius have shown the ability to reduce inflammatory markers in gastric cells.
- Strain-Dependent Effects: Research emphasizes that the immune effects of L. salivarius are strain-specific, with different strains potentially causing different immune responses.
A Comparison of L. salivarius to Other Probiotics
Probiotics have diverse functions, which are highly strain-specific. The table below provides a general comparison.
| Feature | Ligilactobacillus salivarius (e.g., UCC118, LS01) | Lactobacillus rhamnosus (e.g., GG) | Bifidobacterium breve (e.g., BR03) |
|---|---|---|---|
| Primary Function | Strong immunomodulation, mucosal health support in oral and intestinal tracts. | Well-researched for anti-inflammatory effects and preventing infectious diarrhea. | Promotes anti-inflammatory responses and is effective for conditions like atopic dermatitis. |
| Mechanism | Regulates cytokines (increases IL-10), strengthens mucosal barriers, and activates immune cells. Produces antimicrobial bacteriocins. | Adheres well to intestinal lining, competes with pathogens, and modulates cytokine profiles. | Can reduce pro-inflammatory cytokines and increase anti-inflammatory IL-10, especially in combination with other strains. |
| Best For | Targeting oral and intestinal immunity, managing specific inflammatory diseases like colitis or atopic dermatitis. | General gut health, traveler's diarrhea prevention, and eczema. | Atopic dermatitis and other immune-mediated inflammatory skin conditions. |
| Strain Specificity | Effects vary greatly by strain, with different strains potentially inducing opposite immune responses. | Strain GG is extensively studied and known for its high survivability and adherence. | Efficacy is strain-dependent; often used in multi-strain formulations. |
Conclusion
Evidence suggests Lactobacillus salivarius can improve immunity by regulating cytokines, enhancing mucosal barriers, activating immune cells, and optimizing the gut microbiome. Its effects are strain-specific, with different strains having varying abilities to promote anti-inflammatory or Th1-type immune responses. While animal and in vitro studies are promising, more human clinical trials are needed. Consulting a healthcare professional is important before supplementing, especially for those with compromised immune systems. L. salivarius remains an active area of research for targeted immune support.
How to get Lactobacillus salivarius from food
L. salivarius is found in fermented foods such as yogurt, kefir, sauerkraut, kimchi, and some cheeses. Foods rich in prebiotics, like garlic and onions, can also support its growth.
Using Lactobacillus salivarius
Probiotic supplements are available. Look for products with clear strain and CFU labeling and consider third-party tested options. Individuals who are immunocompromised or have damaged heart valves should consult a healthcare provider before use.
