Your microbiome can be shaped by the environment you live in, the food you eat, your genes, and even your age. We know this. But can the people and, perhaps, pets you live with also influence the microorganisms that colonize your body?
Some studies suggest they can, and what’s more you may also change the microbial makeup of the places you frequent, leaving traces of your microbiome behind you.
In order to find out how the microbiomes of people and the places they live in differ from one another, researchers studied the microbial composition of six homes and the people and animals who lived in them. They found more similarities between people, their pets, and their homes than they did between people from different homes (Song et al., 2013).
The research also showed that different residences can have significantly different bacterial profiles. According to the study, although bacteria within homes can vary considerably from room to room, the most substantial similarities occur between the kitchen, front door knob, and bedroom floor. Likewise, the hands and feet of any home’s occupants have the greatest tendency to share the same bacteria.
The same study showed that when a family moves home, their new residence soon has a bacterial composition similar to their old one’s. Along similar lines, the research found that hotel rooms soon acquire their occupants’ bacteria, with a room’s surfaces showing traces of its guest’s microorganisms within 24 hours.
Another study explored the ways in which having children and pets in a household affects its microbiome (Lax et al., 2014). The research showed that the presence of either can lead to a home’s occupants sharing more unique bacteria from their individual guts and skin.
The authors proposed that this could be because of an increase in the number of shared sources of unique microbes. For example, one member of the household might transfer their bacteria to the dog’s bowl as they filled it, then this would be picked up by another person as they performed the same duty later.
The study also showed that dog owners from different families can share microbes which are not shared between people without dogs. The finding reinforces the idea that who we live with, in both human or animal terms, can shape the bacteria which colonize our bodies.
Some researchers suggest that the tendency for individuals to share their microbiomes in such ways may be caused by each of us having a microbial “aura” – a cloud of bacteria which hangs in the air around our bodies wherever we go (Meadow et al., 2015).
Indeed this has led some scientists to propose that it should be possible to identify an individual person from their microbiome alone, then to go on to develop an algorithm capable of matching someone to a specific gut microbiome using metagenomic markers (Franzosa et al, 2014). In fact they were able to identify individuals with an accuracy rate of 80%. However these researchers were unable to identify certain individuals over time, which they proposed was caused by people changing their habits in ways which affected their microbiome.
Written by Catalina and Daniel of the uBiome data science team
1. Cohabiting family members share microbiota with one another and with their dogs.
Se Jin Song, Christian Lauber, Elizabeth K Costello, Catherine A Lozupone, Gregory Humphrey, Donna Berg-Lyons, J Gregory Caporaso, Dan Knights, Jose C Clemente, Sara Nakielny, Jeffrey I Gordon, Noah Fierer, Rob Knight.
2. Longitudinal analysis of microbial interaction between humans and the indoor environment.
Simon Lax, Daniel P. Smith, Jarrad Hampton-Marcell, Sarah M. Owens, Kim M. Handley, Nicole M. Scott, Sean M. Gibbons, Peter Larsen, Benjamin D. Shogan, Sophie Weiss, Jessica L. Metcalf, Luke K. Ursell, Yoshiki Vázquez-Baeza, Will Van Treuren, Nur A. Hasan, Molly K. Gibson, Rita Colwell, Gautam Dantas, Rob Knight, Jack A. Gilbert.
3. Identifying personal microbiomes using metagenomic codes.
Eric A. Franzosa, Katherine Huang, James F. Meadow, Dirk Gevers, Katherine P. Lemon, Brendan J. M. Bohannan, and Curtis Huttenhower.
4. Humans differ in their personal microbial cloud.
James F. Meadow, Adam E. Altrichter, Ashley C. Bateman, Jason Stenson, GZ Brown, Jessica L. Green, Brendan J.M. Bohannan.