Researchers introduced exfoliome sequencing (Foli‑seq) — a targeted, multiplexed amplicon approach that profiles host mRNA from exfoliated gut cells in feces — and demonstrated the method can quantify epithelial and immune transcripts reflecting gut state. Published in Nature Biotechnology, the work showed Foli‑seq detects signals missed by bulk RNA‑seq and can stratify inflammatory bowel disease models and patient samples. The team led by Harris Wang validated the technique in murine colitis models, showing temporal dynamics of epithelial damage, immune responses and recovery; simultaneous microbiome profiling revealed host–microbe interaction networks. The method uses spike‑ins for quantitation and is positioned as a noninvasive tool for longitudinal monitoring of intestinal inflammation and treatment response. Foli‑seq could enable real‑time assessment of gut immunobiology in clinical trials and routine care for IBD, reducing reliance on invasive biopsies and offering a path to mechanistic biomarkers for therapeutic development.