Posted on Jul 05, 2017, 2 a.m.
Researchers discover that the skin microbiome contains the microorganism archaea and that the amount of it varies with age.
New Microorganisms Found on Human Skin
Our skin is full of single cell organisms but in a study out of Berkeley National Laboratory, researchers have found a microorganism on the human skin called archaea (ar-KEY-uh). Archaea is part of the skin microbiome but the amounts vary depending on a person's age and are thought to be an important microbe on the human skin. The study was published in the journal Scientific Reports.
The study involved volunteers aged 1 to 75 years and skin samples were analyzed with chemical and genetic methods. Archaea microorganisms were most abundant in people older than 60 years and younger than 12 years in both male and female participants.
Dryer skin produces more archaea and the microbes may have a role in a cleaning up process. Results obtained from genetic analysis and infrared spectroscopy imaging showed a link between lower levels of sebum which reduces skin moisture, and the increase of archaea microbes.
The Extreme Microbe Archaea
Archaea can live in extreme conditions below the Earth’s subsurface, in the Antarctic ice, and in hot springs. Archaea is different from bacteria and is one of three branches of life on earth (Bacteria, Archaea, Eukarya). Eukarya is the branch that includes all animal and plant life.
The focus is on developing infrared spectroscopy methods to study the microbes. At the Berkley Lab is one of the most powerful machines to generate infrared beams to screen microbes (tell archaea from bacteria). Lack of knowledge on skin archaea is due to the poor diversity of age groups in previous studies, but the new study has revealed that people of middle age have lower levels of archaea on their skin.
NASA Discovers New Strains of Archaea
The current study stemmed from a NASA project in which new methods of cleaning up archaea (a suspected contaminant) during space missions. Certain archaea strains called methanogens could be living in Mars harsh conditions. Other strains found by NASA include thaumarchaeota which can survive in an oxygen environment.
Scientists found that thaumarchaeota were surviving in very clean environments such as hospital rooms and suspected they were coming from the human skin. A small study of 13 volunteers proved the suspicions as archaea were found on their skin. The new follow-up study tested 51 participants. Samples of skin from the chest area were taken. Surprisingly, the differences of archaeal abundance depending on the age. The elderly had an eightfold increase compared to middle-aged participants.
Thaumarchaeota Archaea May be Good For Skin Health
The study's primary focus was on thaumarchaeota archaea which are ammonia-oxidizing and may play an important role because our sweat contains ammonia and a process of nitrogen turnover is good for skin health. The team linked skin dryness to archaeal abundance in the elderly and concluded that people of middle age have higher levels of sebum making for a moister skin. Most known archaea are beneficial to human health and may reduce pH levels in the skin thus reducing susceptibility to infections.
Some bacteria have similar capacities to thaumarchaeota and are used in probiotic skin products to reduce body odor and increase skin moisture. However, further studies are needed before it can be determined if thaumarchaeota has any clinical value.
Future studies will investigate the difference between environmental archaea and archaea found in human skin as well as the physiological role it plays. Researchers are keen to find the different niches archaea live on our bodies. Also important is to find out if archaea are involved in any pathogenic processes (disease or infections) although none have been found so far.
Christine Moissl-Eichinger, Alexander J. Probst, Giovanni Birarda, Anna Auerbach, Kaisa Koskinen, Peter Wolf, Hoi-Ying N. Holman. Human age and skin physiology shape diversity and abundance of Archaea on skin. Scientific Reports, 2017; 7 (1) DOI: 10.1038/s41598-017-04197-4