Lactobacillus salivarius CECT 5713

Lactobacillus salivarius CECT 5713 is a human-origin probiotic strain that produces lactic acid and bacteriocins to competitively exclude pathogenic bacteria in the oral cavity and reproductive tract. Its primary mechanisms involve modulating mucosal immunity, reducing inflammatory cytokines, and restoring microbiome balance in sites including the mouth, gut, and seminal fluid.

Origin & History

Lactobacillus salivarius CECT 5713 (now classified as Ligilactobacillus salivarius CECT 5713) is a probiotic bacterial strain isolated from human breast milk and the feces of a one-month-old breast-fed infant. It belongs to the lactic acid bacteria family and is cultured using standard microbiological isolation techniques like RAPD and PFGE for strain identification.

Historical & Cultural Context

No historical or traditional medicine use has been identified for this strain. L. salivarius CECT 5713 was first isolated in modern research settings from 2006 onward, with no documented links to traditional healing systems.

Health Benefits

• Improved fertility outcomes: 48.1% pregnancy rate vs. 20% placebo in couples with unexplained infertility (placebo-controlled trial, preliminary evidence)
• Reduced oral bacteria: Heat-inactivated strain significantly reduced S. mutans levels from day 3 to 2 weeks (p<0.05, open-label pilot)
• Enhanced reproductive health: 56% achieved successful pregnancy in women with reproductive failure (open-label study, preliminary evidence)
• Infectious mastitis treatment: Effective oral alternative for lactating women (referenced study, limited detail)
• Immune system support: Improved gut microbiota and immune parameters in healthy adults (preliminary evidence)

How It Works

Lactobacillus salivarius CECT 5713 produces lactic acid, hydrogen peroxide, and strain-specific bacteriocins that lower local pH and directly inhibit pathogens such as Streptococcus mutans and anaerobic periodontal bacteria. The strain adheres to mucosal epithelium via surface-layer proteins, competitively excluding pathogenic colonization and stimulating secretory IgA production. It also modulates Toll-like receptor 2 (TLR-2) signaling to downregulate pro-inflammatory cytokines including IL-6 and TNF-α, which may underlie its effects on reproductive and systemic inflammation.

Scientific Research

Clinical evidence consists primarily of open-label and pilot studies, with one placebo-controlled trial in couples with infertility showing 48.1% pregnancy rate vs. 20% placebo (p<0.024). A self-controlled pilot study (PMID: 28950179) demonstrated significant S. mutans reduction, while safety studies in adults (PMID: 20159049) and infants (PMID: 20018483) confirmed tolerability.

Clinical Summary

A placebo-controlled pilot trial in couples with unexplained infertility reported a 48.1% pregnancy rate in the probiotic group versus 20% in placebo, though the small sample size limits generalizability. An open-label pilot study demonstrated that heat-inactivated Lactobacillus salivarius CECT 5713 significantly reduced Streptococcus mutans counts in saliva from day 3 through 2 weeks (p<0.05), suggesting both live and postbiotic forms may have oral health utility. Evidence remains preliminary across all indications, with most trials being small, short-duration, or lacking double-blind design, meaning results should be interpreted cautiously. Larger, well-powered randomized controlled trials are needed to confirm efficacy in fertility, oral microbiome modulation, and any systemic immune applications.

Nutritional Profile

Lactobacillus salivarius CECT 5713 is a live bacterial strain with no meaningful macronutrient or micronutrient contribution at standard probiotic doses (typically 1×10⁸ to 1×10⁹ CFU per serving). Its bioactive value lies in its metabolic byproducts: produces lactic acid (lowering local pH to inhibit pathogens), bacteriocins (antimicrobial peptides targeting gram-positive competitors including S. mutans and certain vaginal pathogens), and short-chain fatty acids including acetate. The strain synthesizes small quantities of B vitamins (B12, folate, B6) as metabolic byproducts in situ, though concentrations are insufficient to serve as a dietary source. It expresses surface-layer proteins (S-layer proteins) and lipoteichoic acids that mediate direct immune signaling via Toll-like receptor 2 (TLR-2) and TLR-4 pathways. Heat-inactivated (postbiotic) forms retain immunomodulatory cell wall components but lose colonization and acid-producing capacity. Bioavailability is strain-dependent and site-specific — CECT 5713 demonstrates notable colonization affinity for both oral mucosa and vaginal epithelium, which underpins its dual-site efficacy in reproductive and oral health contexts.

Preparation & Dosage

Clinically studied at approximately 10^9 CFU/day (9 log10 CFU/day) for up to 6 months in reproductive health studies using viable strains. Heat-inactivated form used as salivary rinse for oral health benefits over 2 weeks. Consult a healthcare provider before starting any new supplement.

Synergy & Pairings

Lactobacillus salivarius CECT 5713 pairs effectively with Lactobacillus rhamnosus GG or L. reuteri RC-14, as these strains occupy complementary vaginal and intestinal niches, collectively reinforcing microbial barrier integrity through overlapping bacteriocin production and competitive exclusion of Gardnerella vaginalis and Candida species. Prebiotic fructooligosaccharides (FOS, ~3–5g dose) selectively feed Lactobacillus species including CECT 5713, increasing viable CFU counts and lactic acid output in the gut-reproductive axis, amplifying colonization persistence. Folate (400–800mcg methylfolate form) and zinc (15–25mg zinc bisglycinate) complement the reproductive health pathway by supporting oocyte quality and sperm DNA integrity in parallel with CECT 5713's proposed microbiome-mediated fertility mechanisms, creating additive rather than redundant support across hormonal, oxidative, and microbial dimensions of reproductive function.

Safety & Interactions

Lactobacillus salivarius CECT 5713 is generally considered safe for healthy adults, with adverse effects in trials limited to mild, transient gastrointestinal symptoms such as bloating or loose stools. Individuals who are immunocompromised, have central venous catheters, or are recovering from major surgery should consult a physician before use, as rare cases of Lactobacillus bacteremia have been reported with probiotic strains as a class. Concurrent use with broad-spectrum antibiotics may reduce the strain's viability and efficacy; spacing administration by at least 2 hours from antibiotic dosing is commonly recommended. Safety data in pregnancy and lactation specific to this strain are limited, and use during pregnancy should be discussed with a healthcare provider despite the general tolerability of Lactobacillus species in this population.