Inactivated lactic-acid bacteria (tyndalized, lysate). Marketed as a skin probiotic. Real clinical evidence comes from small RCTs in atopic dermatitis. Pregnancy-safe and low-allergenicity.
Topical application
CWeak evidence. In vitro data, open-label studies, or expert consensus.
Postbiotic activity is supported by small RCTs in atopic dermatitis. On healthy skin without inflammation there are no significant effects. Traffic light YELLOW – narrow application niche, general probiotic marketing is overstated.
Under the INCI Lactobacillus, cosmetics use inactivated cells and fragments of lactic-acid bacteria of the Lactobacillus genus (L. bulgaricus, L. acidophilus, L. plantarum, L. paracasei). Since live bacteria do not survive in cosmetics – they are killed by preservatives, manufacturing heat, and pH changes – the ingredient is almost always: • Tyndalized – cells killed by fractional heating with preserved cell walls and peptidoglycans. • Lysate – cells disrupted, including cytoplasm, enzymes, and peptides. • Filtrate – the post-fermentation phase with metabolites. INCI: Lactobacillus. Claimed effects. Marketing promotes the ingredient as: 1. Probiotic/postbiotic – skin microbiome balance, suppression of S. aureus. 2. Immunomodulator – via activation of TLR-2/TLR-4 receptors. 3. Barrier booster – through local inflammation reduction. Actual evidence. A series of RCTs in atopic dermatitis patients showed that L. johnsonii lysate reduces SCORAD by 20-30% after 8 weeks of topical use (Gueniche 2008). Similar data exist for L. paracasei. Effects in acne and other inflamed skin are more modest. On healthy skin without inflammation, cosmetics with lactobacilli usually do not produce a noticeable shift in microbiome composition. Pregnancy safety. Topical use is safe. Systemic absorption is absent – the components are too large. Inactivated cells do not replicate and produce no systemic probiotic effects. Skin tolerance. Low irritation and allergen potential. Non-comedogenic. Suitable for sensitive and atopic skin. What not to count on. If the INCI lists just Lactobacillus without specifying the strain and form (tyndalized, lysate, filtrate), the activity cannot be evaluated – the manufacturer may put different technological feedstocks under this label.
Irritation potential
LowAllergen risk
LowPregnancy
SafeLactobacillus is considered safe during pregnancy at typical cosmetic concentrations. Systemic absorption through the skin is minimal.
Lactobacillus suits: normal, dry, combination, oily, sensitive.
Inactivated lactic-acid bacteria (tyndalized, lysate).
On the Fulton scale 0/5 – non-comedogenic. For acne-prone skin, a rating of 3 or higher suggests choosing an alternative.
The INCI name is Lactobacillus. It may also appear as: Inactivated Lactobacillus, Lactobacillus Ferment, Лактобактерии.
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Suitable for