Welcome to the online database presented in the article "Site-specific programming of the host epithelial transcriptome by the gut microbiota" by Sommer et al. The gut microbiota has a major impact on a wide range of physiologic processes in the host. The intestinal epithelium not only separates us from the microbiota but also interacts with it and thereby impacts host immune status and physiology. Our previous study investigated microbiota-induced responses in the gut and other tissues (Larsson et al., 2012, Gut). Here, we used microarray analysis of laser capture microdissection (LCM)-harvested epithelial fractions from germ-free and conventionally raised mice and mice during colonization to investigate microbiota-induced transcriptional responses in defined epithelial fractions. Above you can query the database for the expression pattern of specific genes in ileal and colonic tip and crypt epithelial fractions.