Ancient people used to eat raw meat before invention of fire. I have read it in history book. They would kill animals and eat their flesh. Can you eat raw meat at present time? I think you will be afraid of virus and bacteria. Recently you have heard that covid-19 infection ocurred when one or few people ate Bat in China. Did ancient people also have a viral infection? As far as I know that they would kill animals and eat raw meat before invention of fire. In this way, they lived their life. It shows that probably their immune system would be more stronger than people living in today’s world. Disclaimer: I don’t have any information regarding ancient people living before invention of fire. This is my assumption only.