Benefits
Caries risk reduction (WB21)
Caries risk reduction (WB21): 2.0×10⁹ CFU/day for 2 weeks significantly decreased mutans streptococci (P=0.039) — the primary cariogenic bacteria. A comparison vs TI 2711, Ovalgen® DC, and xylitol showed WB21 and TI 2711 lactobacilli increases. Foundational caries-prevention evidence for the WB21 strain.
Periodontal health heat-killed CP3365
Periodontal health (heat-killed CP3365): a double-blind randomized placebo-controlled trial significantly inhibited increases in plaque control record, bleeding on probing, and probing pocket depth (P<0.05). 16S rRNA showed Porphyromonas, Fusobacterium, and Haemophilus relative abundance significantly decreased. Postbiotic application — non-viable bacteria carrying clinical activity.
Gut barrier UCC118
Gut barrier (UCC118): fermented milk-borne L. salivarius UCC118 in healthy adults significantly increased fecal enterococci and lactobacilli, while bifidobacteria, coliforms, and bacteroides remained unchanged. Selective microbiota modulation evidence supporting gut barrier and probiotic ecology applications.
CECT5713 immune support (Sierra et al.)
CECT5713 immune support: L. salivarius CECT5713 increased fecal bifidobacteria with stability of bacteroidetes, clostridia, and enterobacteria. Immune support strain with a selective microbiota modulation profile.
Ls-33 obesity / gut barrier
Ls-33 obesity / gut barrier: an Ls-33 fecal microbiota study in obese adolescents supports an obesity and gut barrier indication; strain-specific application distinct from oral health and immune strains.
Strain-specific clinical evidence
L. salivarius shows distinct strain-specific evidence across indications — WB21 (oral health), CP3365 (periodontal heat-killed postbiotic), UCC118 (gut), CECT5713 (immune), Ls-33 (metabolic), LS01/DSM 22775 (atopic dermatitis), LI01 (liver/intestinal inflammation), PS2 (metabolic). Generic L. salivarius supplements are not equivalent to evidence-based strains.
Surface protein gut adherence
L. salivarius has surface proteins supporting gut adherence and sustained colonization. Distinguishes from transient-transit probiotics — supports persistence in the gut beyond intake duration.
Mechanism of action
Strain-specific bioactivity
Different L. salivarius strains exhibit distinct clinical evidence and bioactivity profiles. Foundation principle: L. salivarius is not monolithic — strain-specific selection determines clinical relevance for any given indication.
Surface protein gut adherence + colonization
Surface proteins enable gut adherence and sustained colonization — moves beyond transient-transit probiotic ecology.
Mutans streptococci reduction (oral)
WB21 and related oral-health strains directly reduce S. mutans (the primary cariogenic bacterium) and other oral pathogenic bacteria.
Lactic acid + bacteriocin production
Lactic acid production lowers local pH; bacteriocin production provides targeted antimicrobial activity. Multi-mechanism antimicrobial activity profile.
Anti-inflammatory immunomodulation (Ls-33)
Ls-33 murine models — gut barrier improvement and anti-inflammatory immunomodulation. Mechanistic basis for the metabolic and obesity applications.
Postbiotic heat-killed activity (CP3365)
Heat-killed CP3365 retains clinical activity without live bacteria — postbiotic application. Useful in immunocompromised populations or where live probiotics are not desired.
Clinical trials
WB21 randomized open-label trial plus short-term 8-volunteer administration (UMIN000013160). 2.0×10⁹ CFU/day for 2 weeks significantly decreased mutans streptococci (P=0.039).
Clinical population described in trial publication.
WB21 randomized open-label trial plus short-term 8-volunteer administration (UMIN000013160). 2.0×10⁹ CFU/day for 2 weeks significantly decreased mutans streptococci (P=0.039). Earlier comparison vs TI 2711, Ovalgen® DC, and xylitol — WB21 and TI 2711 lactobacilli increases. Foundational caries-prevention evidence.
Heat-killed CP3365 (UMIN000045656) double-blind clinical trial (n=64) × 8 weeks.
Clinical population described in trial publication.
Heat-killed CP3365 (UMIN000045656) double-blind clinical trial (n=64) × 8 weeks. Significantly inhibited increases in plaque control record, bleeding on probing, probing pocket depth (P<0.05). 16S rRNA: Porphyromonas, Fusobacterium, Haemophilus relative abundance decreased. Postbiotic application.
Ls-33 fecal microbiota study in obese adolescents.
Clinical population described in trial publication.
Ls-33 fecal microbiota study in obese adolescents. Obesity and gut barrier indication evidence; metabolic-strain application.