Ethical permission and registration
The study was conducted in accordance with the Declaration of Helsinki and Good Clinical Practice. Written informed consent was obtained from all participants. Ethical approval was obtained from the regional ethical review board in Stockholm, Sweden (2017/1815-31). The study was registered with EudraCT number 2017-002418-30. The Swedish Medical Products Agency concluded that their approval of the study was not required as clindamycin was not used as an investigational medical product and the autologous faecal matter could not be categorized as a medical product. Since the faecal samples were collected at home for research purposes, the biobank regulations were not applicable, and the samples did not need to be registered in a biobank.