JAMA - Nontoxigenic Clostridium difficile M3 for Prevention C dif

"Administration of Spores of Nontoxigenic Clostridium difficile Strain M3 for Prevention of Recurrent C difficile Infection"

"Conclusions and Relevance  Among patients with CDI who clinically recovered following treatment with metronidazole or vancomycin, oral administration of spores of NTCD-M3 was well tolerated and appeared to be safe. Nontoxigenic C difficile strain M3 colonized the gastrointestinal tract and significantly reduced CDI recurrence."

https://jama.jamanetwork.com/article.aspx?articleid=2281703