In a new study from McGill University, researchers bring science into an unexpected setting: a tattoo parlor. In this first characterization of the human piercing microbiome, the uniquely human cultural practice of piercing serves as a model system to help us better understand how biological communities (re)assemble after catastrophic environmental disturbances.
The process of piercing typically begins with sterilization of the skin, which removes the resident microbes. The piercing itself then creates a new environment that differs from the previously unpierced skin in many ways and serves as a ‘clean slate’ for a new microbial community to colonize.
“We know from anthropology and sociology that piercings are uniquely human symbols of expression, connection, and identity,” says Charles Xu, the Biology PhD student who led the study. “With this study, we've shown that skin piercings also represent an unintentional act of ecosystem self-engineering of the ecological landscape that is the human skin.”
From October 2019 to March 2020, researchers recruited 28 individuals who were receiving earlobe piercings at Tattoo Lounge MTL in Montreal. Skin swab samples were collected before participants got an ear piercing and several more times during the two weeks after the piercing. The study’s findings shed light on how a sudden event like a piercing can lead to a fundamental shift in skin microbiomes. The piercing site showed an increase in the number of unique DNA sequences and species compared to the unpierced controls, indicating an increasingly diverse and ecologically complex microbiome at the piercing site. This microbiome is dominated by two antagonistic species, Cutibacterium acnes and Staphylococcus epidermidis, with the moist piercing environment allowing the latter to gain the upper hand.
With this newfound understanding of the skin piercing microbiome, Xu says the study lays the groundwork for further research regarding other kinds of piercings, the tattoo microbiome, and even the prevention and control of skin infections.
Looking beyond the human body, Xu’s supervisor Professor Rowan Barrett says that studies like this one could potentially help inform our understanding of the biological consequences of large-scale, catastrophic environmental events.
“Piercings represent a nice tractable model to gain better understanding of the general processes involved in community assembly following environmental change” Barrett says. “If we understand these processes, we might be able to incorporate policies or engage in active management practices to aid the recovery of biological communities.”
About the study
Community assembly of the human piercing microbiome by Charles C.Y. Xu, Juliette Lemoine, Avery Albert, Élise Mac Whirter, and Rowan Barrett was published in Proceedings of the Royal Society B: Biological Sciences.
