An international team of researchers led by Israel’s Weizmann Institute, has used bacteriophages (good viruses) to kill inflammation-causing gut bacteria that cause inflammatory bowel diseases (IBD) such as Ulcerative Colitis and Crohn’s. “Good” bacteria are not harmed.
https://m.jpost.com/health-and-wellness/article-713952/amp
https://www.israel21c.org/study-shows-viruses-can-kill-gut-bacteria-of-crohns-bowel-disease/