Here are some good writeups about phages:
https://forums.phoenixrising.me/threads/bacteriophage-therapy-phage-therapy-for-gut-infections-dysbiosis-%E2%80%94-just-30-instead-of-1200.41244/

https://cfsremission.com/2018/06/27/phages-101/

There's a klebsiella pneumonia phage sold on this russian site