Lactobacillus Ferment

What it is

Lactobacillus ferment is the product of fermenting a nutrient medium with Lactobacillus bacteria. It contains lactic acid, peptides and other metabolites - the live bacteria themselves are not present in the finished cosmetic. It is marketed as a "postbiotic" and used to support the skin's own microbial balance.

What it does well

• Hydrates and may help support the skin barrier

  Fermentation metabolites are humectant and there is growing laboratory interest in microbiome-supporting effects, but robust independent human trials on cosmetic use remain limited.

  Limited evidence

Worth knowing

• "Microbiome" claims outpace the evidence

  Marketing often implies a proven rebalancing of skin flora. The science is early-stage and finished-product effects are hard to attribute to the ferment alone.

  Matters most toAnyone paying a premium for microbiome positioning.

Where the EU stands