Respuesta :
The prefix that changes the meaning of bacterial from "relating to or caused by bacteria" to "preventing bacteria" is "pro-" to "anti-". Relating or caused by bacteria is "probiotic" whereas for preventing bacteria, it is "antibiotic". Hope this answers your question. Have a nice day!
Answer: Your answer would be anti
Explanation:
This is because anti mean to stop or to prevent (antibiotic)