On Feb. 18, 2025, scientists from the Institute for Systems Biology announced they have developed a breakthrough method to track diet using stool metagenomic data.

The new method, called MEDI (Metagenomic Estimation of Dietary Intake), detects food-derived DNA in stool samples to estimate dietary intake. MEDI leverages stool metagenomics, which refers to sequencing all the DNA present in fecal samples (including microbial, human, and food-derived DNA).

This non-invasive, data-driven approach offers an objective alternative to traditional food diaries and questionnaires, which are still the gold standard in dietary assessment but can suffer from misreporting and compliance issues.

Leveraging a database of more than 400 food items and over 300 billion base pairs of genomic information, MEDI accurately detected food intake patterns in infants and adults, and across two controlled feeding studies.

With further development, MEDI could transform nutrition science, epidemiological studies, and clinical trials, allowing researchers, doctors, and individuals to track diet-related health risks with unprecedented ease. The full study was published in Nature Metabolism.