Scientists Develop Crappy New Way to Estimate a City's Obesity...Literally

Information about the health of a town could someday be tracked by the tiny organisms present in the local sewage, a new study suggests.

Scientists were able to accurately estimate a city's obesity level based on analysis of gut microbes found in sewage samples. (Photo credit: Shutterstock)

Research by the Marine Biological Laboratory in Woods Hole, Massachusetts, and the University of Wisconsin, Milwaukee, found that by analyzing sewage for microbes common in the human gut, they could identify a "healthy microbiome" in the population or one that might be experiencing some issues, like obesity.

“This work fits into our long-term goal of developing better water pollution and public health assessments,” Sandra McLellan with the University of Wisconsin said in a statement.  “It’s a great example of how new sequencing technologies and novel computational approaches can allow us to glean new information from complex environments.”

The study published in the latest issue of the journal mBio involved comparing the gut bacteria of 137 healthy individuals to the bacteria in 200 sewage samples from 71 cities in the U.S. The scientists found that those living in the same area have some a set of gut bacteria in common, a news release from MBL stated. The study then was able to compare the types of bacteria they were seeing to known statistics on a city's obesity percentage.

According to the MBL news release, the type of bacteria researchers found in a sample could predict a city's obesity level with between 81 to 89 percent accuracy.

“This method is similar to trying to create a map of a geographical region,” A. Murat Eren, an assistant research scientist at the MBL, said in a statement. “The way we have been working with microbiomes of individuals has been similar to driving around and mapping the streets and structures of a city in a detailed manner. This approach takes our efforts to a much larger scale. In this sense it is similar to taking one big aerial picture of a city, trading off intricate details of a small number of well-described streets for broader insights and larger patterns.”

“The sewage samples of 71 cities do not tell us anything specific about ‘individuals’ who live in those cities," Eren said. “However, only using sewage samples, we were able to differentiate these cities based on their estimated level of obesity. This approach can be beneficial to answer various public health questions while not compromising the privacy of individuals. For instance, microbial observatories plugged into sewage systems can keep us informed about the general health of large populations without being intrusive.”

Randy Seeley, who studies obesity at the University of Michigan, shared his thoughts on the research with Inside Science.

"Had they shown up in my office with this idea I would have said 'you're nuts, there's no way you can pull that off,'" he told the science publication. "The fact that they are capable of doing it just shows you the power of the big-data approach."

Seeley added that he thinks traditional surveys will continue to be the norm for estimating obesity or other factors in a population, but he said that this new method could be used to evaluate the results of a health program.

(H/T: Reddit)

—

Front page image via Shutterstock.

—

This story has been updated to correct a misspelling of MBL from MLB.