A scientist demonstrates application of the experimental therapy to the inner elbow. For demonstration purposes, the bacteria solution has been replaced with purple dye Photo by:.NIAID
Topical application of live Roseomonas mucosa bacteria strains taken from healthy human skin was safe for adults and children with atopic dermatitis (AD) and was associated with reduced disease severity, according to early findings from an ongoing clinical trial at the U.S. National Institutes of Health (NIH).
The findings, published in JCI Insight (May 2018;3(9):e120608), are from research that followed up on earlier findings in mouse and cell models of AD. In the earlier investigation, R. mucosa collected from healthy volunteers improved outcomes in these models, whereas R. mucosa from human patients with AD worsened outcomes in the models.
“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 Dr. Anthony S. Fauci, director of NIH’s National Institute of Allergy and Infectious Diseases (NIAID), in a press release. “New, inexpensive therapies that require less frequent application are needed to expand the options available for atopic dermatitis treatment.”
This research was inspired in part by growing evidence that the skin microbiome—the community of micro-organisms living on human skin—play a significant role in the etiology of AD. “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 the trial’s principal investigator, NIAID’s Dr. Ian Myles, in the release. “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.”
To test the safety and potential benefit of live R. mucosa application in individuals with AD, a Phase 1/2 study, known as Beginning Assessment of Cutaneous Treatment Efficacy for Roseomonas in Atopic Dermatitis (BACTERiAD), is being conducted at the NIH Clinical Center in Bethesda, Md. The experimental treatment was first used in 10 adult volunteers with AD. Twice a week for six weeks participants sprayed a solution of sugar water with increasing doses of R. mucosa—strains isolated from healthy individuals and cultured in a lab—onto their inner elbows and one other skin area of their choice. All participants were also instructed to continue their current AD treatment regimens. Those participants did not report any adverse reactions or complications. Most experienced improvements in their atopic dermatitis, and four weeks after stopping the bacteria therapy, some reported needing fewer topical steroid applications.
Five volunteers aged nine to 14 years with AD were recruited next. In this group the bacterial treatments were applied to all affected skin areas twice a week for 12 weeks, and then every other day for four more weeks. This group also experienced no complications or adverse effects, and most experienced improvements in their AD, and a reduced need for topical steroids. Treatment was also associated with a decrease in S. aureus on the children’s skin.
The investigators note that larger, placebo-controlled studies are needed to confirm the findings, but the observation of more than 50% improvement in AD severity in more than half of the subjects in both the adult and child participants suggests that the additional research is warranted. .
Investigators also examined whether molecules produced by R. mucosa or present in certain skin care products could be associated with AD. They found that R. mucosa strains isolated from patients with AD produced irritants, while strains from patients with healthy skin produced molecules that improved the skin barrier function and aided in immune regulation. They also found that some parabens, commonly used as preservatives in skin care products, impaired the growth of R. mucosa strains isolated from healthy skin, but did not impair growth of either S. aureus or R. mucosa from AD skin.