Can Other People’s Genes Affect Your Body?

Close Ties: We were already well aware that roommates could influence the state of the kitchen sink. However, new research suggests they might also be leaving a mark in a place far less visible. A study published in Nature Communications hints that the people or animals you live with could be influencing the mix of microbes living inside you.

The Study: The research, led by scientists in the U.K., looked at what happens when animals share close quarters. In rats, the team found that genetic factors promote the growth of certain gut bacteria, but those microbes do not stay put. When rats lived together, bacteria linked to one animal’s genetic makeup spread to its cage mates. Over time, their gut microbiomes began to resemble one another, even when the animals were genetically different.

The Takeaway: These findings add nuance to a growing body of evidence that the gut microbiome plays a vital role in health. They also indicate genes may shape not only an individual’s disease risk, but also the disease risk of people around them.

Keep In Mind: This was a rat study, so researchers are careful not to overextend the findings to humans just yet.