Expression data of colonic epithelial cells colonized with B. theta. Mus musculus

The gut microbiota is essential for several aspects of host physiology such as metabolism, epithelial barrier function and immunity. Previous studies have revealed that host immune system as well as diet and other environmental factors have a strong impact on the composition and activity of gut microbiota, but the molecular requirements for such functional regulation remain unknown. We show that the bacteria belonging to phylum Bacteroidetes acquire their symbiotic activity in the colonic mucus, depending on a newly characterized molecular family encoded within the polysaccharide utilization loci (PUL), which we have named Mucus-Associated Functional Factor (MAFF). We used microarray analysis of colonic epithlial cells to determin the impact of MAFF genes on colonic homeostasis. Overall design: Specific pathogen free mice were treated with antibiotics (metronidazone and ciprofloxacin) and then colonized wild type or MAFF-deleted mutant of B. theta. Colonic epithelial cells were FACS-purified 4-weeks after colonization, and RNA samples were prepared.