Atopic dermatitis (AD) can be characterized by an impaired skin barrier function, susceptibility to Staphylococcus aureus skin infections, immune dysregulation, and cutaneous dysbiosis (impaired microbiota).
“Current understanding of the microbiome’s influence on human health has expanded far beyond the original hygiene hypothesis,” researchers stated in the study.
A previous clinical trial investigated the potential role that Gram-negative skin bacteria played in eczema and revealed that isolates of one particular bacterium, Roseomonas mucosa (R. mucosa), collected from healthy volunteers improved eczema outcomes in mice by improving its skin barrier and improving eczema-like rashes.
More specifically, researchers discovered that R. mucosa directly killed Staphylococcus aureus, a common eczema and skin irritation causing bacteria.
“These preclinical results suggested that interventions targeting the microbiome could provide therapeutic benefit for patients with [eczema],” wrote the researchers.
To investigate this hypothesis, 10 adult and five pediatric patients were enrolled in an open-label phase I/II safety and activity trial
Topical good bacteria solution
The adult and guardians of pediatric participants sprayed a solution containing the beneficial bacteria (R. mucosa) to the inner elbows twice per week for a total of six weeks.
For each dose, patients or parental guardians of the pediatric patients were instructed to empty the contents of an eyedropper into a sprayer vial, wait two to five minutes for reconstitution, and then spray the affected area. All patients reported compliance with all 12 doses.
Patients returned for clinical assessment after completion of the full six weeks of therapy and were contacted remotely 30 days after treatment.
Need for larger clinical trial
According to researchers, R. mucosa was associated with clinical improvement in adults and children with eczema.
The six-week treatment was associated with significant reduction in objective intensity of eczema and reduced subjective regional severe itching of the skin. However, these positive results were found to be true for the inner elbow region only as treatment on the hands did not yield any improvement in eczema symptoms.
“Failure of R. mucosa to impact hand disease may indicate that higher treatment doses would be needed, a different species or strain of bacteria would be required, or that hand disease is not amenable to microbiome treatment,” researchers wrote.
“However, given the increased contact with topical antimicrobials on the hands, this finding may also be a consequence of environmental exposures promoting dysbiosis.”
Based on the study’s results, researchers plan to launch a bigger trial with hundreds of patients to further prove these findings.
Want to learn about the latest advances in research into the human microbiome? Join us in Miami next month (June 5-7) for Probiota Americas.
Learn more about the event here, including a full list of speakers and how to register.