So you might be wondering whether we can also do this sort of thing across species, and it turns out that if you take microbes from an obese person and transplant them into mice you've raised germ-free, those mice will also become fatter than if they received the microbes from a lean person, but we can design a microbial community that we inoculate them with that prevents them from gaining this weight.
では生物種間でもこうなるのだろうか という疑問が湧いてくると思います 肥満の人の微生物を 無菌の環境で育ったマウスに移植すると 痩せた人の微生物を 移植した時より太りましたが 肥満を抑制する微生物を培養して マウスに移植する事もできます