What’s in the Sewer Reveals What’s On the Menu

A technology turns wastewater into a powerful window into community nutrition in North Carolina

The following is a summary of a story by Shantell Kirkendoll on Duke University School of Medicine.

What goes down the drain may reveal more about a community’s diet than any food diary ever could.

A new Duke University and UNC-Chapel Hill study found that wastewater can provide an surprisingly accurate picture of what entire communities are eating. By analyzing tiny fragments of plant and animal DNA in sewage, researchers identified regional eating habits across 19 North Carolina communities.

The study, published in the Proceedings of the National Academy of Sciences, introduces a DNA sequencing tool called FoodSeq-FLOW. The system detects traces of food left behind in wastewater, offering an objective alternative to traditional nutrition surveys, which often rely on people’s memories and may miss underserved communities.

The findings reflected differences in geography, economics and demographics. Coastal communities showed more evidence of seafood consumption, including drum and Spanish mackerel. Wealthier neighborhoods were more likely to show traces of hops, a key ingredient in beer. Communities with larger foreign-born populations showed more evidence of tropical fruits and beans.

Researchers said that FoodSeq-FLOW offers a way to monitor diets across communities to help target food security programs. “Poor diet is one of the world’s biggest drivers of chronic disease, but we’ve never had a fast objective way to measure what people eat,” said Lawrence A. David, Duke professor of molecular genetics and microbiology. “This study helps fill that gap so we can better connect diet to health.”

Rachel T. Noble, professor of marine sciences at UNC-Chapel Hill, added about the technology, “The result is a snapshot of the community that helps understand where resources are needed.”

For more information, go to Duke University School of Medicine.