While burgeoning research into our gut microbiome is revolutionizing medical science, this isn't the only part of our body that is home to large populations of symbiotic bacteria. Our skin also holds a complex array of micro-organisms, many of which we are only just discovering offer beneficial effects. New research has revealed treating the skin with a specific beneficial bacteria can help relieve symptoms of atopic dermatitis (eczema), reducing the need for traditional topical steroids.

Prior research from scientists at the National Institute of Allergy and Infectious Diseases (NIAID) revealed that a bacterium called Roseomonas mucosa improved symptoms of atopic dermatitis in animal and cell culture models. The team then set out to examine if these results were transferable to human subjects and recently published the successful results from a Phase 1 human clinical trial.

Ten adult subjects with atopic dermatitis were treated twice a week for six weeks with a spray solution containing live Roseomonas mucosa bacteria. No adverse effects were seen from the treatment and most participants reported improvements in their symptoms. A subsequent` cohort of younger subjects aged between nine and 14 years were recruited and demonstrated similar positive results.

"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," says Ian Myles, a scientist working on the trial.

This Phase 1 study is only intended to initially demonstrate the safety of the approach, but the team is now moving onto a Phase 2 study that will include larger numbers of subjects and a vital placebo group to better demonstrate efficacy. One of the more interesting results from this early trial was the ongoing effects of the bacterial treatment, with some subjects reporting a need for fewer topical steroids to manage their condition, weeks after stopping the therapy.

"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," says Myles.

Research is only just beginning to explore the broader systemic effects possibly caused by alterations in our skin microbiome. For example, a recent study from the University of California, San Diego School of Medicine uncovered a strain of bacteria present on the skin that could inhibit the development of some skin cancers.

Further work from the NIAID team has uncovered major differences in the strains of Roseomonas mucosa between healthy subjects and those with atopic dermatitis. Certain irritants were found to be produced by Roseomonas mucosa strains on those with dermatitis that were not seen on healthy subjects. It is also hypothesized that some common skin products (such as those containing forms of parabens) can block the growth of beneficial strains of Roseomonas mucosa. More research needs to be done before any clear conclusions can be derived but it is suggested that certain common skin products may be worsening the effects of atopic dermatitis by disrupting the skin microbiome.

The study was published in the journal JCI Insight.

Source: National Institute of Allergy and Infectious Diseases (NIAID)