A postbiotic is a preparation of inactive microorganisms and/or their components that confers a health benefit on the host.
Esse uses Lactobacillus in many forms – sometimes whole and alive, sometimes whole but killed and sometimes the contents of the broken cells are used. When you see the INCI listing “Lactobacillus”, it means that the probiotic bacteria are whole with the cell membrane intact – either alive or dead (Level 3 or 4).
In Esse products, when you see “Lactobacillus Ferment”, it means that the cells have been broken (lysed) and the cell contents have been used (Level 2).
In some products, Esse will use both whole bacteria and lysed bacteria, so you will see both Lactobacillus and Lactobacillus Ferment in the INCI list.
In products from some other brands Lactobacillus Ferment can mean that the product contains an extract from the growing medium and not the cells (Level 1 in the video).
All the extraction techniques can yield useful ingredients for skincare.
Tyndallised Lactobacillus is a version of probiotic extracts where the Lactobacillus has been inactivated or killed using heat.
In this technique, the microbes are kept whole but they are inactivated at low temperature. This process is called tyndallisation. Traditionally the culture of probiotics is heated to 60˚C and cooled again over three days. This kills the probiotic cells, so the cfu per ml would still be 0. Esse has developed a process that allows us to inactivate the microbes at a lower temperature, so that the proteins on the cell surface remain unchanged. These probiotics can then still dock onto skin cells but obviously can’t grow and divide to significantly alter the skin’s microbiome.
Skin cells are equipped with receptors that can recognise beneficial bacteria and these receptors operate on a lock-and-key mechanism that will respond to dead microbial cells. Skin cells then adjust immune responses and make changes that influence barrier function.
These responses are complex, but it has been found that Lactobacillus treatment (even with deactivated cultures) increases the formation of tight-junctions, both in gut epithelial cells, and in skin cells. Tight-junctions improve the barrier function of skin, allowing it to better regulate the passage of microbes and substances. Tight-junctions keep water in and everything else out, minimising the number of triggers to the skin’s immune system.
Esse uses this technology in the majority of leave-on products in the range at a rate of 1 million microbes per ml.
These probiotic extracts are called lysates because the probiotic cells are ruptured (lysed) under high pressure to release the cell contents. In this technique, the probiotics are again cultured in a nutrient-rich substrate, which is then filtered off, keeping the intact cells. These cells are then broken so that their cell contents leak out. The cell solids are then removed. This method results in an “extract” that contains the cytoplasm (cell contents) of probiotic microbes.
The AMPs present in Lactobacilli lysates are capable of killing competing species or inhibiting their growth. AMPs will shift the populations of bacteria on the skin. Healthy skin microbes are able to grow in the presence of Lactobacillus AMPs, but these are toxic to opportunistic microbes.
Esse uses this technology in the majority of its BIOME+ products.
No actual microbes – just the broth they leave behind
These products use the “broth” from a microbial fermentation. The microbes are grown on a substrate (think of this as a watery solution of microbial nutrients) and then the probiotic microbes are filtered off. The “broth” is the remaining solution (which has the metabolites of the microbes in it.) This is used as an ingredient in a final cosmetic product. Good skin care results can sometimes be obtained using this technique, but Esse does not refer to this technology as “probiotic” or include it in its BIOME+ claims.