Recently, the term of gut environment has been attracted in the relationship with health and diseases. In this background, the possibility of "microbiome-based drug or medicine" using useful bacteria are expected to have therapeutic effects on various diseases. In this talk, I will introduce the possibility of Blautia as a candidate of microbiome-based drug, which we found in a cohort study of Japanese people, which is expected to be effective against obesity and diabetes. I will also outline the regulatory research to realize the microbiome-based drug.