One test plot was experimentally burned each year, one was burned every three years, and one was left completely intact.

每年试验性地烧毁试验地， 每三年烧毁，有完无损。

So currently, the US Food and Drug Administration only allows doctors to use fecal transplants experimentally for battling one of the toughest gut infections — antibiotic-resistant Clostridiodes difficile.

目前，美国食品药品监督管理局（FDA）只允许医生试验性地通过粪菌移植对付种最严重的肠道感染疾病——耐抗生素梭状芽胞杆菌感染。