Sharing Microbes: What Living Together Means for Your Microbiome
When you start living with a partner, a lot of changes come into play. Your routines shift—bedtimes, breakfast choices, and even the microbes that inhabit your body. A recent study published in Cell Press Blue reveals that couples who cohabit share around 44% of their oral microbiome and 19% of their gut microbiome.
This study draws from microbiome DNA data of 430 individuals spanning 207 households in Italy and Fiji. Previous studies hinted at the idea that roommates or family members might share microbiomes, but this research quantifies that sharing, especially within romantic partnerships. Vitor Heidrich, a computational biologist from the University of Trento, remarked that it’s intriguing to explore the origins of these microbes since humans are born without them.
Ilana Brito, a biomedical engineering professor at Cornell University, commented on the significance of the findings, especially regarding the oral microbiome, which has typically been challenging to study. She stressed that if people exchange saliva, like through kissing, it could lead to increased sharing of microbiome strains among romantic partners.
However, how exactly are these microbes transmitted? Heidrich speculates it might happen through sharing meals or, believe it or not, toothbrushes touching in the bathroom. Romantic partners tend to share more of their oral microbiome compared to just housemates. Heidrich notes, “It’s a neat confirmation that direct saliva exchange leads to more strain sharing.”
As for gut microbiomes, couples share approximately 19% of theirs, regardless of their relationship status. Heidrich acknowledged that the idea of sharing gut microbes might be a bit unsettling, as it implies possible ingestion of minute amounts of fecal matter from housemates. This concept can be hard to wrap your mind around, yet he indicates it’s a likely scenario.
While most bacteria are harmless—some even beneficial—Heidrich noted that certain transmissible microbes may be associated with health risks. For instance, many transmissible species in the study were linked to a higher risk of Type 2 diabetes.
Dr. Jessica Queen from Johns Hopkins University remarked that these findings prompt significant questions about the impact of one’s household microbiome on disease risk. Heidrich is cautious about making broad claims just yet, emphasizing that the field is still exploring these possibilities.
The interaction between microbiomes and illness is likely a two-way street. It’s challenging to determine causation vs. correlation, as the gut hosts trillions of bacteria, and establishing the sequence of events can be intricate.
Despite these complexities, Heidrich reflects on his domestic life, mentioning he shares a home with his wife and two cats. He seems unperturbed about the microbial exchange, particularly concerning pets, since they come with distinct gut environments. He posits that humans have coexisted closely for millennia, sharing microbes almost inherently as part of life.
While researchers acknowledge it could take years to establish whether these findings lead to specific health recommendations, there remains an ongoing need for more extensive, long-term studies. Brito concluded that exchanging microbes isn’t something to be avoided, as it’s an intrinsic part of human living.
