Scientists have developed a new method called FoodSeq-FLOW that analyzes DNA in municipal wastewater to track what entire communities are eating. According to Gram Research analysis, researchers tested this technique on wastewater from 21 treatment plants serving 2.1 million people in North Carolina and successfully identified 184 plant foods and 116 animal foods at a cost of less than one penny per person. The method revealed that dietary patterns vary significantly by income level, education, immigration status, and geography—for example, coastal communities ate more local seafood while areas with more immigrants consumed more tropical fruits and beans.
Researchers developed a groundbreaking method called FoodSeq-FLOW that analyzes DNA from food in municipal wastewater to understand what entire communities are eating. By studying wastewater samples from 21 treatment plants serving 2.1 million people in North Carolina, scientists identified 184 different plant foods and 116 animal foods. This innovative approach costs less than one penny per person and could help public health officials track nutrition patterns in real-time without asking people what they eat. The method revealed interesting patterns: wealthier communities ate different foods than lower-income areas, coastal towns ate more local seafood, and areas with more immigrants had more tropical fruits and beans.
Key Statistics
A 2026 research study analyzing wastewater from 21 North Carolina treatment plants serving 2.1 million people identified 184 plant foods and 116 animal foods using DNA sequencing, with 98% accuracy for animal-derived food identification.
According to research reviewed by Gram, the FoodSeq-FLOW wastewater dietary analysis method costs less than one penny per person and showed a 64% correlation with individual dietary data collected from stool samples.
A 2026 analysis of 183 wastewater samples revealed that community dietary patterns correlated with per capita income, education levels, immigration status, and coastal geography, demonstrating that wastewater DNA analysis can detect socioeconomic and geographic dietary signatures.
Research published in the Proceedings of the National Academy of Sciences found that seasonal shifts in detected food taxa in wastewater matched regional food availability patterns, validating the accuracy of DNA-based dietary surveillance.
The Quick Take
- What they studied: Can scientists figure out what people in a community are eating by analyzing the DNA in wastewater from treatment plants?
- Who participated: Wastewater samples from 21 treatment plants across North Carolina that serve approximately 2.1 million people. The study included 183 separate wastewater samples collected over time.
- Key finding: Scientists successfully identified 184 plant foods and 116 animal foods in wastewater samples, with the results matching individual dietary data 64% of the time. The method costs less than one penny per person.
- What it means for you: This new tool could help governments and health officials understand eating patterns across entire communities without surveys or questionnaires. It may help identify nutrition problems and guide public health decisions, though it’s still a new technology being tested.
The Research Details
Researchers developed a new laboratory technique called FoodSeq-FLOW that looks for plant and animal DNA in wastewater. They collected wastewater samples from 21 different treatment plants across North Carolina over several months, analyzing 183 total samples. The technique works by finding specific DNA sequences from food—plant DNA from chloroplasts and animal DNA from mitochondria—that survive digestion and appear in sewage.
To test if their method worked accurately, the scientists compared the wastewater results to dietary information collected directly from individual people’s stool samples. They also tracked how the types of food detected changed with the seasons and compared dietary patterns across different neighborhoods and income levels.
The entire process is remarkably affordable, costing less than one cent per person to analyze. This makes it practical for large-scale use across many communities simultaneously, unlike traditional dietary surveys that are expensive and time-consuming.
Traditional ways of tracking what people eat—like surveys and food diaries—are expensive, time-consuming, and people often don’t answer honestly. This new wastewater method provides an objective, real-time snapshot of community eating patterns without relying on people to report their own diets. It’s also scalable, meaning it could be used across entire regions or countries using existing wastewater treatment infrastructure.
The study was published in the Proceedings of the National Academy of Sciences, one of the world’s most respected scientific journals. The researchers validated their method by comparing wastewater results to individual dietary data, showing a moderate-to-strong correlation (64%). The technique successfully identified 98% of animal-derived food sequences correctly. The large sample size (2.1 million people across 21 plants) and multiple validation approaches strengthen the findings.
What the Results Show
Scientists successfully detected 184 different plant foods and 116 animal foods in wastewater samples from across North Carolina. The DNA-based dietary profiles from wastewater matched individual dietary data collected separately with a 64% correlation, suggesting the method accurately reflects what people are actually eating. The cost was remarkably low at less than one penny per person analyzed.
When researchers tracked the same wastewater treatment plants over time, they observed seasonal patterns in food types that matched expected regional food availability. For example, certain fruits and vegetables appeared more frequently during their growing seasons, confirming the method captures real dietary changes.
The analysis revealed striking differences in food consumption across communities. Wealthier neighborhoods showed different dietary patterns than lower-income areas. Communities with higher education levels had distinct food signatures. Coastal towns showed higher consumption of local seafood, while areas with larger immigrant populations consumed more tropical fruits and beans.
The study found that beer ingredients in wastewater correlated with discretionary income levels, suggesting that wealthier communities consumed more beer. This demonstrates the method can track not just basic foods but also processed beverages and ingredients. The 98% accuracy rate for identifying animal-derived food sequences indicates the technique is highly reliable for protein sources. Geographic location proved to be a strong predictor of dietary patterns, with coastal proximity showing the clearest dietary signature.
This research extends wastewater-based epidemiology, a field that previously focused on tracking disease pathogens and drug use in communities. According to Gram Research analysis, this is the first large-scale application of wastewater DNA analysis to dietary surveillance. Previous dietary tracking methods relied on surveys, food purchase data, or individual food diaries—all of which have significant limitations. This wastewater approach offers a completely new, objective perspective on community nutrition patterns that complements existing methods.
The study was conducted only in North Carolina, so results may not apply to other regions with different food systems or populations. The 64% correlation with individual dietary data, while encouraging, means the method isn’t perfect—some dietary information is lost or unclear. The technique detects what’s in wastewater but can’t identify individual eaters or track specific people’s diets. Seasonal variations in food availability may make it harder to compare communities in different climates. The method works best for communities with centralized wastewater systems and may be less useful in areas with septic systems or limited infrastructure.
The Bottom Line
Public health agencies should consider piloting FoodSeq-FLOW in their wastewater treatment systems to establish baseline community dietary patterns. This method works best as a complement to, not replacement for, traditional dietary surveys. Communities interested in nutrition policy should explore using this tool to identify dietary disparities and track changes over time. (Confidence: Moderate—this is a new technology showing promise but needs more real-world testing.)
Public health officials, nutrition policy makers, and city planners should pay attention to this research. Food industry analysts and market researchers may find value in understanding community food preferences. Communities concerned about nutrition equity and health disparities could use this tool to identify problems. This research is less immediately relevant to individual consumers making personal dietary choices, though it may eventually inform public health recommendations.
If adopted by wastewater treatment plants, this method could provide dietary data within weeks of implementation. Meaningful trends would likely emerge after 3-6 months of continuous sampling. Seasonal patterns would become clear after one full year of data collection. Long-term monitoring over multiple years would be needed to track how community diets change over time.
Frequently Asked Questions
Can scientists really tell what people eat by looking at sewage?
Yes. Scientists can identify plant and animal DNA in wastewater that survives digestion. A 2026 study of 2.1 million people found 184 plant and 116 animal foods in sewage samples, matching individual dietary data 64% of the time.
How much does it cost to test wastewater for food DNA?
Less than one penny per person. This makes it affordable for large-scale community dietary surveillance using existing wastewater treatment infrastructure.
What can wastewater food DNA tell us about communities?
Wastewater analysis reveals dietary patterns linked to income, education, immigration status, and geography. Wealthier areas show different foods than lower-income neighborhoods; coastal towns eat more local seafood; immigrant communities consume more tropical fruits and beans.
Is this method accurate enough to replace food surveys?
Not yet. The 64% correlation with individual dietary data is promising but imperfect. It works best alongside traditional surveys, providing objective community-level data that surveys cannot capture.
Could this wastewater method track individual people’s diets?
No. The method only reveals what entire communities are eating collectively. It cannot identify specific individuals or their personal dietary choices, protecting privacy while providing population-level insights.
Want to Apply This Research?
- Track your community’s seasonal food availability by comparing your personal food purchases to the wastewater-detected seasonal patterns. Log which seasonal fruits and vegetables you buy each month and compare to regional availability data.
- Use community-level dietary data to identify underconsumed food groups in your area and intentionally increase your intake of those foods. If your community shows low seafood consumption, try adding fish or shellfish to your weekly meals.
- Monitor your neighborhood’s dietary trends by checking wastewater analysis reports (if your city publishes them) quarterly. Compare your personal diet to community patterns to see if you’re eating similarly to or differently from your neighbors. Track how your food choices align with seasonal availability detected in wastewater data.
This research describes a novel laboratory technique for analyzing community-level dietary patterns through wastewater analysis. It is not intended to diagnose, treat, or provide personalized nutrition advice. Individual dietary needs vary and should be discussed with a healthcare provider or registered dietitian. This wastewater method provides population-level data only and cannot assess individual nutritional status or health risks. While the technique shows promise, it is still in early development and has not yet been widely implemented in clinical or public health settings. Results from North Carolina may not apply to other regions with different food systems, climates, or wastewater infrastructure. Anyone making dietary changes should consult with a qualified healthcare professional.
This research translation is published by Gram Research, the science division of Gram, an AI-powered nutrition tracking app.