S u m m a r y :
Microorganism archaea are present on your skin, and you don’t even know it!
Bacteria Are Not the Only Ones
We all know that bacteria are all over our skin, and deep inside of us. We are not alone—other organisms live intimately with(in) us. Guess what now, bacteria are not the only ones. Scientists have recently discovered that human skin is characterised by an abundance of yet another living thing, the archaea.
What Are Archaea?
They are single-celled microbes that constitute a whole different category of organisms (the other two are bacteria and eukaryotes, the latter including plants and animals). Archaea have no nucleus in their cells, nor do they have any other cell organelle enclosed by membranes.
Usually, when we mention microorganisms living on human skin, we tend to think of bacteria only. The new study, though, puts things into perspective.
“The skin microbiome is usually dominated by bacteria,” says senior author Hoi-Ying Holman. “Most of the scientific attention has been on bacteria, because it’s easier to detect. Based on the literature, six years ago we didn’t even know that archaea existed on human skin. Now we’ve found they’re part of the core microbiome and are an important player on human skin.”
Archaea & Extreme Environments
Their distribution usually concentrates in environments of extreme conditions like very high or low temperature; for instance, some species of archaea live in hot springs while yet others reside in the ice of Antarctica. Further studies also show their presence in sediments as well as in the subsurface of the Earth. It is only recently that we have spotted their presence in the human gut.
Archaea Prefer Children & The Elderly
Holman and his team analysed samples taken from skin of human participants from the age group 1-75. They not only found that archaea was yet another tenant living on the skin but also that they were in greater abundance in very young (<12) and very old volunteers (>60).
The researchers had performed both genetic and chemical analyses on the microbiome samples.
Archaea Like Dry Skin
Another interesting finding is that gender does not appear to be a determining factor in terms of the abundance of the organism. Rather, skin type has more implications for the differences, as the results show that dry skin has an increased of archaea. Corresponding author Christine Moissl-Eichinger says that lower levels of sebum (characterising dry skin) is linked with a greater number of archaeal signatures displayed by the genetic results. According to her, archaea might be involved in the cleaning processes for dry skin conditions.
Why did we not find archaea on human skin before?
The authors also mention a lack of studies focusing on archaea on human skin. They blame both technical and methodology limitations. An example of the latter is that previous studies have not included much age diversity in sampling. The age factor would affect results as the new findings show that middle-aged people have less archaea than their younger and older counterparts.
Purpose of Archaea on Skin?
What do the archaea do on human skin? Holman suggests a role in promoting skin health through sweat.
Nothing is confirmed yet, but it is believed that they are beneficial and not harmful to human health.