Bacteria found in wastewater may provide clues about community health, including rates of chronic disease, health behaviors and social conditions, according to a recent study from The Ohio State University.
The research, published in the journal Environmental Research, expands on applications of wastewater monitoring, which became more widely used during the COVID-19 pandemic. The findings suggest the same approach could offer a practical way to understand broader health patterns across communities.
"During the pandemic, the world learned how to use wastewater to track infectious disease. We asked, what else can it tell us?" said Emma Lancaster, the study's lead author and a former doctoral student in Ohio State's College of Public Health.
Lancaster, now an environmental health consultant in Boston, began exploring the idea while working with wastewater samples collected for COVID-19 surveillance. She wondered whether the same samples could reveal broader patterns in public health.
For the study, researchers analyzed 27 wastewater samples from nine treatment plants serving eight Ohio cities in 2022. The communities were home to more than 1.3 million people in a mix of urban and rural areas.
The team evaluated bacteria in the wastewater - specifically those found in the human gut. Then they compared what they found with public data on chronic diseases, health behaviors, demographics and socioeconomic conditions.
The researchers saw distinct bacterial profiles across the cities, highlighting significant differences in the community-wide gut-associated microbiome. Several types of bacteria were associated with community rates of obesity, high blood pressure, asthma and other chronic conditions. They also found associations with smoking, depression, physical activity and unemployment.
One finding stood out: The amount of a bacterial group called Desulfovibrio was associated with eight health measures, including obesity, high blood pressure, stroke and several chronic diseases.
Rural communities generally had higher abundance of these bacteria, and of several chronic health conditions.
"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.
Wastewater monitoring could help policymakers and public officials better identify communities facing greater health challenges and direct resources where they are needed, she said.
That broad view is one of wastewater monitoring's biggest advantages, said Jiyoung Lee, professor and chair of environmental health sciences at Ohio State and the study's senior author.
"Wastewater offers a unique way to understand the health of whole communities, not just the people who show up in clinics," Lee said.
The approach could eventually expand wastewater monitoring beyond infectious diseases to help evaluate broader public health efforts, the researchers said.
"It already helps us track viruses including those that cause COVID, flu and Mpox, and it has potential to support investigations of foodborne illness, such as the recent Cyclospora outbreak," Lee said.
"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."
This work was partially funded by the Ohio Department of Health.
