Wastewater Bacteria Linked to Chronic Disease Rates in Ohio Study

Each city's sewage carried a distinct bacterial profile, showing significant differences in community-wide, gut-associated microbiomes. Several bacterial types tracked with community rates of obesity, high blood pressure, asthma and other chronic conditions. The team also found associations with smoking, depression, physical activity and unemployment.

Why did one bacterium stand out?

One finding led the pack. The abundance of a bacterial group called Desulfovibrio correlated with eight separate health measures, more than any other microbe the researchers measured.

Rural communities generally had more of these bacteria, and they also had higher rates of several chronic health conditions. That overlap matters because rural health gaps are well documented but hard to monitor.

"In many cases, poor health outcomes are worse in rural areas, and to see these distinct indicators of poorer gut microbiome health in these rural areas offers us clues to some of what is driving that," Lancaster said.

What could this change for public health?

The study is preliminary in an important way: it shows associations, not causes. The researchers can't yet say the bacteria drive disease, only that their presence in sewage mirrors a community's health profile. The sample was also small — 27 samples from nine plants — so the findings will need replication in larger, more diverse regions before officials can act on them.

If the approach holds up, though, wastewater monitoring could help policymakers identify struggling communities and direct resources where they're needed. That's a real advantage over clinic-based data, which only captures people who show up for care.

"Wastewater offers a unique way to understand the health of whole communities, not just the people who show up in clinics," said Jiyoung Lee, professor and chair of environmental health sciences at Ohio State and the study's senior author.

The practical appeal is scale. Nine treatment plants covered more than 1.3 million residents — roughly one monitoring point per 145,000 people — a ratio no survey or screening program can match.

Where does monitoring go from here?

Wastewater surveillance already tracks the viruses behind COVID-19, flu and mpox across the country. Lee said it also has potential to support investigations of foodborne illness, pointing to the recent Cyclospora outbreak as an example.

The new findings point further. "Now, our findings suggest its value could extend beyond infectious agents — for example, tracking community gut microbiome changes could eventually help us assess whether nutrition programs are improving gut health," Lee said.

That last step remains a long-term goal. For now, the Ohio data shows the sewage flowing under eight cities carries a readable signature of chronic disease — one that public health agencies may learn to read.