Just this past weekend, I found myself in a conversation with an octogenarian who was born and raised in the USA but has been living abroad in the developing world for the last twenty-odd years. He noted that each time he returns to the States, he encounters the same intestinal reactions as those who have travelled to visit him in foreign (read: less sanitary) lands. Well, science may have figured out a cause for such a reaction.

Welcome To The Neighborhood, Germs

Location determines makeup of germs more than other factors

As it turns out, each city, town and neighborhood carries with it a combination of microbes unique to that specific place. In other words, the germ signature that creates your unique makeup is quite similar to the guy who sells you bread in the morning, but is probably completely different from the school teacher living in a neighboring state.

Science has learned to distinguish a city not by it’s food and fashion trends, nor by it’s political affiliation. Now, it’s all about the germs.

Measuring microbes in office setting leads to discovery

This discovery came about as researchers were attempting to measure microbes in an office. Instead, they discovered that they could differentiate the germs simply by knowing from which city they originated.

Furthering the investigation, what stood out was that it didn’t appear to matter what office the germs came from. The research team found that even when each office within a specific city was vastly different, they each carried the same basic microbe signature. This fascinating finding comes despite the fact that offices have a huge variety of factors that scientists in the past would have suspected significantly changed germ makeup within that setting. Things such as usage patterns, ventilation systems, sizes, etc. seem to have little impact on which microbes are contained within the employees of these different offices. In the end, geography was the greatest factor in determining what germs were found.

They also found that the microbes have little to no change with the passage of time.

During the test period, germs were collected from a variety of office types in the vastly different cities of San Diego, California; Toronto, Ontario, Canada; and Flagstaff Arizona.

As senior study author J. Gregory Caporosa notes, “We suspect that in the absence of extreme conditions like flooding, microbes may be passively accumulating on surfaces in the built environment rather than undergoing an active process.” Dr. Caprosa, PhD, is an assistant professor of biological sciences and assistant director of the Center for Microbial Genetics and Genomics at Northern Arizona University. “As we continue to expand our understanding of the microbiology of the built environment, possibly including routine monitoring of microbial communities to track changes that may impact human health, our results will help inform future research efforts,” he speculated.

“The findings were especially interesting, because even within each city the offices we studied differed from each other in terms of size, usage patterns, and ventilation systems,” he continued, “suggesting that geography is more important than any of these features in driving the bacterial community composition of the offices within the ranges that we studied.”

So we return to my companion, whom I mentioned at the beginning of the article. Perhaps it’s not only about the level of health and safety laws that are in place within a country, but more so how our bodies adjust to unfamiliar microbial communities that exist in any city outside of our own. The unfamiliar composition can wreak havoc on a person’s health as they travel, regardless of the destination.