Furthermore, co-housing experiments revealed that Drd5−/− single-housed mice and co-housed mice (housed with WT mice) still had a higher presence of colitis-associated microbiota (assessed by 16s rRNA sequencing), such as Prevotellaceae and Clostridia_UCG-014, and lower abundance of protective bacteria, including Bacteroidaceae and Tannerellaceae. The gene discussed is DRD5; the disease is colitis.