NIH: Topical treatment with live Roseomonas mucosa — a bacterium naturally present on the skin — was safe for adults and children with atopic dermatitis (eczema) and was associated with reduced disease severity, according to initial findings from an ongoing early-phase clinical trial at the National Institutes of Health. Preclinical work in a mouse model of atopic dermatitis had suggested that R. mucosa strains collected from healthy skin can relieve disease symptoms. The new findings, published May 3 in JCI Insight, support further evaluation of this potential new therapy.
Atopic dermatitis is an inflammatory skin disease that can make skin
dry and itchy, cause rashes and lead to skin infections. The disease is
linked to an increased risk of developing asthma, hay fever and food
allergy. Atopic dermatitis is common in children and sometimes resolves
on its own, but it also can persist into or develop during adulthood.
“Living with atopic dermatitis can be physically and emotionally
challenging. While treatment can help manage the symptoms, currently
available therapies can be time-consuming — requiring multiple daily
applications — and costly,” said Anthony S. Fauci, M.D., director of
NIH’s National Institute of Allergy and Infectious Diseases (NIAID).
“New, inexpensive therapies that require less frequent application are
needed to expand the options available for atopic dermatitis treatment.”
The cause of atopic dermatitis is unknown, but studies suggest that
the skin microbiome—the community of bacteria and other microbes living
on the skin—plays a key role. For years, scientists have known that
people with atopic dermatitis tend to have large populations of Staphylococcus aureus
bacteria on their skin. These bacteria can cause skin infections and
trigger immune responses that increase inflammation and worsen
Recent work by NIAID researchers using mouse and cell culture models
of atopic dermatitis revealed that treatment with isolates of R. mucosa collected from the skin of healthy people improved disease outcomes in the models. In contrast, R. mucosa isolates from people with atopic dermatitis either had no impact or worsened outcomes in the models.
Based on these preclinical findings, NIAID investigators designed an
early stage clinical trial to test the safety and potential benefit of a
treatment containing live R. mucosa in people with atopic dermatitis. The Phase 1/2 study is being conducted at the NIH Clinical Center in Bethesda, Maryland.
“By applying bacteria from a healthy source to the skin of people
with atopic dermatitis, we aim to alter the skin microbiome in a way
that will relieve symptoms and free people from the burden of constant
treatment,” said NIAID’s Ian Myles, M.D., the principal investigator of
the trial. “If future clinical studies demonstrate that this strategy is
effective, we hope our work will lead to development of new, low-cost
atopic dermatitis therapies that do not require daily application.”
The researchers first tested the experimental treatment in 10 adult
volunteers with atopic dermatitis. Twice a week for six weeks, the
volunteers sprayed a solution of sugar water containing increasing doses
of live R. mucosa onto their inner elbows and one additional skin area of their choice. The R. mucosa
strains included in the treatment were originally isolated from the
skin of healthy individuals and grown under carefully controlled
laboratory conditions. Participants were instructed to continue their
normal eczema treatments, including topical steroids and other
Participants did not report any adverse reactions or complications.
Most participants experienced improvements in their atopic dermatitis,
and four weeks after stopping the bacteria therapy, some reported
needing fewer topical steroids.
The investigators next enrolled five volunteers aged 9 to 14 years
with atopic dermatitis. Treatments were applied to all affected skin
areas twice weekly for 12 weeks and every other day for an additional
four weeks. Consistent with the findings in adults, there were no
complications or adverse effects, and most participants experienced
improvements in their eczema, including a reduced need for topical
steroids. The researchers also found that treatment was associated with
decreases in the S. aureus population on the children’s skin.
Although larger studies comparing the bacteria therapy with a placebo
will be required to assess the effectiveness of this potential
treatment, the investigators observed a greater than 50 percent
improvement in atopic dermatitis severity in four of the five children
and six of the 10 adults. The researchers are continuing to monitor the
five children who received treatment and are enrolling additional
children into the study.
To better understand factors that may contribute to imbalances in the
bacteria on the skin, the scientists also investigated whether
chemicals produced by R. mucosa or present in certain skin products may be associated with atopic dermatitis. They found that strains of R. mucosa
from people with atopic dermatitis produced skin irritants, while
strains isolated from healthy skin produced chemicals that may enhance
the skin’s barrier and help regulate the immune system. In addition,
some forms of parabens—a common preservative in skin products—and some
topical emollients (moisturizers) blocked the growth of R. mucosa from healthy skin and did not have as strong an effect on growth of S. aureus or eczema-associated R. mucosa.
These findings suggest that certain products may worsen atopic
dermatitis and/or affect the effectiveness of microbiome-based
Final results from the ongoing study at NIH will provide the
foundation for larger trials to evaluate the efficacy of this novel
investigational therapy, as well as to better understand the role of R. mucosa in
atopic dermatitis. NIH has exclusively licensed the technology to Forte
Biosciences to advance this potential new therapy through further
For more information about the study, known as Beginning Assessment of Cutaneous Treatment Efficacy for Roseomonas in Atopic Dermatitis (BACTERiAD), please see ClinicalTrials.gov using identifier NCT03018275. The study is no longer enrolling adults but is currently recruiting pediatric participants aged 3 to 17 years.
NIAID conducts and supports research — at NIH, throughout the United
States, and worldwide — to study the causes of infectious and
immune-mediated diseases, and to develop better means of preventing,
diagnosing and treating these illnesses. News releases, fact sheets and
other NIAID-related materials are available on the NIAID website.