Pig Pen is vindicated! We emit clouds of microbes (a microbial aura!) wherever we go, shedding a million particles per hour. Our clouds are our unique bacterial fingerprint, and we share our clouds with others. These clouds can be detected in buildings, elevators, and anywhere people go. It is possible to identify people who were in a room through analyzing the microbial clouds in that room. This allows for useful forensic evidence when other material evidence has been washed away or disposed of. Kind of like an "i"cloud DNA-style identification system! Your microbial cloud is a reflection of your diet, your personal care products (deodorants, shampoos, perfumes, soaps...), drugs, exposure to nature (dirt, air, water, plants, bugs...), many other factors and each other!
Your personal microbiome consists of the total microbial population of your skin, gut, genitals, ears, nose, lungs, mouth, eyes, and aura. Microbial cells outnumber human cells 10:1 and microbial DNA outnumber human DNA 200:1, thus you are actually more microbial than human! It seems that we should tend to our microbiome since it is crucial to our health and immunity. Diet and lifestyle make a huge impact on the microbiome.
"Hey, you, get off of my cloud". Remembering Mick Jagger and the 1965 hit song by the Rolling Stones! Stretching those lyrics to this topic: We all know what it's like to recoil at someone else's scent (natural or cosmetic). Consider that at a more subtle level, we may be reacting to the other person's microbial cloud too. Keeping company with environmentally healthy people is probably a very good habit!
For more information http://www.yalescientific.org/2016/02/you-have-a-microbial-cloud/