Is it possible that our personal hygiene routines make us too clean? Are we soaping and cleansing away friendly microbes that help preserve skin health? A study presented at the 5th American Society for Microbiology Conference on Beneficial Microbes in Washington, DC, provides food for thought on these questions.
Researchers from the biotech company AOBiome are developing a skin product that they hope will one day treat skin disorders like acne and ulcers by restoring levels of a friendly type of bacteria known as ammonia-oxidizing bacteria (AOB).
AOB metabolize ammonia, a major component of sweat. They are also everywhere in soil and water and important to the nitrogen cycle and nitrification processes in the environment.
In the new study, researchers from AOBiome showed how human volunteers using an AOB solution reported better skin condition and appearance compared with a placebo group.
The researchers were testing the idea that because the ammonia oxidation products nitrite and nitric oxide are important for skin functions like inflammation, relaxing blood vessels and wound healing, then AOB might have a similar effect by consuming ammonia.
For their blinded, placebo-controlled study they used Nitrosomonas eutropha, an ammonia-oxidizing bacterium found in organic soil.
They recruited 24 human volunteers and randomized them to two groups. One group applied a solution containing a suspension of live Nitrosomonas to their face and scalp for a week, while the other group did the same except unknown to them, their solution only contained a placebo.
The researchers took skin swabs from the volunteers at the start of the study - before applying any of the solutions. DNA tests on the samples showed none of the volunteers had AOB on their skin.
The study lasted 3 weeks. Neither group used hair products for the first and second week, and they returned to their normal routine for the third week.
Volunteers who used the bacteria solution reported improvements in skin condition
At the end of the study period, the volunteers who used the AOB solution reported improvements in skin conditions compared with little or no improvements reported by the placebo group.
Skin swabs taken during and immediately after the first week showed AOB were present in 83-100% of samples from the volunteers who used the active solution, but none in the ones from placebo users.
Swabs taken at the end of the second week showed presence of AOB in 60% of those taken from the AOB users, and again none in those taken from placebo users.
The results also showed that improvement in skin condition correlated with levels of AOB found in the swab samples.
Further tests showed that the AOB changed the mix of bacteria present on the skin - the skin microbiome. None of the AOB users showed adverse reactions to application of AOB.
Dr. Larry Weiss, Chief Medical Officer at AOBiome, says:
"This study shows that live Nitrosomonas are well tolerated and may hold promise as novel, self-regulating topical delivery agents of nitrite and nitric oxide to the human skin."
He says they are now planning to carry out clinical trials to test how well AOB treats acne and diabetic ulcers in human patients.
This news follows reports of a UK study presented at another scientific meeting in April 2014, that showed how skin bacteria play an important role in wound healing.