While I agree that scat play can be hazardous to your health, I feel that if your donor is healthy, the risk to the recipient is very low. And the idea that bacteria change for each person makes no sense. Bacteria is bacteria. That's why antibiotics work.
I also watch a lot of scat porn...
FWIW, I am an older man who has been into the scat scene my whole life. I have tasted the poop of maybe 2 dozen women, and licked the anus of hundreds. I have never gotten any illness from my hobbies. Also, the injection of fecal matter is an alternative treatment to several severe digestive...