Columbia University researchers introduced exfoliome sequencing (Foli‑seq), a targeted amplicon approach that profiles host RNAs from exfoliated gut cells in feces to monitor intestinal and immune activity in near real time. Murine colitis models and human IBD samples showed that fecal feRNA captures epithelial injury, immune responses, and recovery dynamics, enabling patient stratification and host–microbe interaction mapping. A complementary Nature paper validated Foli‑seq’s quantitative performance and sensitivity, demonstrating the technique’s robustness for longitudinal, noninvasive gut transcriptomics. Developers say the method can augment microbiome profiling and support biomarker‑driven IBD management and therapeutic monitoring without invasive endoscopy.