Think hotel rooms are gross? An elegant study led by Jack Gilbert, published Thursday in Science Reports, suggests that our resident microbes could help ease our minds on this issue, as they very quickly populate hotel rooms (and houses, more on that below) to make our hotels microbiologically identical to our homes within 24 hours.
In the study, a number of families, including some families that moved to a new house, were followed to determine the microbial communities associated with these families and their homes. The abstract nicely summarizes the scope and findings of the study:
“The bacteria that colonize humans and our built environments have the potential to influence our health. Microbial communities associated with seven families and their homes over 6 weeks were assessed, including three families that moved their home. Microbial communities differed substantially among homes, and the home microbiome was largely sourced from humans. The microbiota in each home were identifiable by family. Network analysis identified humans as the primary bacterial vector, and a Bayesian method significantly matched individuals to their dwellings. Draft genomes of potential human pathogens observed on a kitchen counter could be matched to the hands of occupants. After a house move, the microbial community in the new house rapidly converged on the microbial community of the occupants’ former house, suggesting rapid colonization by the family’s microbiota.”
Because the data were able to show which rooms in the homes various family members had been in and when, it seems that, at least in the built environment, the microbial fingerprint belonging to individuals is quite strong. Jack Gilbert takes this one step further, discussing potential applications to forensics in a Washington Post article, where he is quoted as saying “If someone is, shall we say, recently and inappropriately deceased, we can look at their bacterial colonies and try to identify who the last person to come into contact with them was, and when. An actual fingerprint is rarely left on a body, but a microbial fingerprint certainly is.”
Only time will tell whether these microbial fingerprints can be used in forensics or other fields/applications, but the implications of this study are really exciting.
The forensic application is interesting. I wonder if the contact with someone else’s microbial fingerprint would be enough to linger on, though? What if the contact is just too brief or the victim’s microbiome competitively excludes or alters the attacker’s fingerprint, or they just mesh together?