These images illustrate the diversity of interactions between the microbial residents on skin. Each spot is composed of a different microbe isolated from face swabs of human subjects.

We wanted to understand how antagonism between bacteria affects the stability and transmissibility of the skin microbiome. We analyzed hundreds of images like this, to construct a network of interactions between skin bacteria. From this network we uncovered a striking finding: while toxin-producing antagonist bacteria are common, it is rare to find an antagonist bacteria and sensitive victim bacteria on the same person. Put another way, if a toxin producer is colonizing skin, only microbes that are resistant to this toxin can survive. 

Working towards these personalized therapies is an exciting area of research.