Columbia University researchers published a method called Foli‑seq (fecal exfoliome sequencing) in Nature Biotechnology that amplifies host transcripts from exfoliated gut cells in stool to profile intestinal and immune activity noninvasively. The team validated the assay in mouse colitis models and human IBD samples, showing it can detect inflammation‑linked transcriptional changes not captured by bulk RNA‑seq. Foli‑seq uses targeted multiplexed amplicon sequencing with spike‑in controls for quantitative comparisons over time and across treatment responses. Investigators demonstrated temporal resolution of epithelial injury, immune activation, and microbiome–host interaction networks, and stratified IBD patient subgroups by disease severity. The work offers a scalable, longitudinal molecular tool for drug developers and clinical teams seeking minimally invasive biomarkers for patient selection, pharmacodynamic readouts, and real‑time disease monitoring in IBD trials.