The microbiome is known to play a major role in gut health, but what about our skin? Billions of bacteria reside there, and the probiotic types may hold great potential to prevent infections during wound healing.

Our skin provides a natural barrier to the environment. This is crucial for our health, as skin protects us from invasive pathogens such as bacteria and viruses.

When the skin barrier is damaged, these pathogens are ready to make their way into the body to colonize it. This is particularly dangerous if the bacteria in question cause widespread damage to skin or other tissues, and if they are resistant to antibiotics.

Staphylococcus aureus is naturally present in the noses of around 30 percent of the population and mostly does not cause harm. However, when the skin barrier is broken, S. aureus can cause severe infection.

S. aureus is notorious for forming biofilms. When this happens, the bacteria attach to a surface - such as the skin - and sugar molecules form a protective matrix around the bacteria. Biofilms are mostly resistant to antibiotics and are therefore a considerable health risk.

If S. aureus spreads to the blood it can cause sepsis, which is a major cause of death in children who have experienced severe burn injuries.

Pseudomonas aeruginosa, which is another pathogen known to form biofilms, is often found in infected burn wounds. Normally resident in the gut, this pathogen invades and colonizes the skin - followed by other organs such as the liver and lungs - in immunocompromised individuals such as burn patients.

Although antibiotics are used in wound treatments, multidrug resistance is common and infections persist. Scientists are searching for alternatives. Could bacteria provide much-needed strategies to prevent life-threatening infections?

Probiotic bacteria show promising potential

Do bacteria have antibacterial properties? Yes, they do; they naturally compete with each other for living space and food. To achieve this, bacteria produce antimicrobial molecules that specifically prevent the growth of other bacteria by altering the growth environment in their favor and by disrupting communication between other bacterial cells.

Catherine O'Neill, Ph.D. - senior lecturer in the Division of Musculoskeletal and Dermatological Science at the University of Manchester in the United Kingdom - and her team have tried to harness these properties by using bacteria to prevent pathogen infections.

But does skin harbor suitable bacteria? In response to that question, Dr. O'Neill told Medical News Today, "We really don't have any idea of skin probiotics. We don't know enough about the skin's microbiome and how it interacts with the wound."

Instead, she uses lactobacillus bacteria, which are a group of so-called friendly bacteria, in her research. Lactobacilli are mostly harmless and some strains are a crucial component of our daily lives in that they facilitate the fermentation of products such as yogurt, beer, and wine.

Dr. O'Neill's team showed that both L. rhamnosus GG and L. reuteri could protect skin cells in the laboratory from infection by S. aureus. This was true when live bacteria were added to the skin cells and when the bacteria were killed and their extracts added instead.

In a recent study published in the journal Scientific Reports, Dr. O'Neill further showed that the two lactobacilli had different effects on skin cells in a wound healing model.

L. rhamnosus GG mostly promoted cell migration, allowing the cells to close the artificial wound rapidly, while L. reuteri increased rates of cell division, helping to replenish the pool of cells destroyed by the creation of the wound. This study used bacterial extracts rather than living cells.

Dr. O'Neill told MNT that she sees bacterial extracts as a safer way to treat patients because there are incidences when lactobacillus bacteria have entered into the bloodstream of immunocompromised patients and caused harm.

"I doubt you'd get any clinician to put live bacteria onto a wound [in the U.K.]," she explained. "We'd have a lot more success getting a dead organism through ethics committees."

Medical News Today