DRD5 and colitis: Moreover, DRD5−/− single-housed mice and cohoused mice had slightly high abundance of colitis-associated microbiota, such as Prevotellaceae and Clostridia_UCG-014, and low abundance of protective bacteria, including Bacteroidaceae and Tannerellaceae, which indicating DRD5−/− mice have a weak tendency to develop colitis (Fig. S3C).