Some labs made bacteria-free mice for research purposes. They're viable. So "not be able to live" is a stretch. Human body does use some bacteria in the guts,

Some labs made bacteria-free mice for research purposes. They're viable. So "not be able to live" is a stretch. Human body does use some bacteria in the guts, but a lot of those very same bacteria would absolutely try to eat the entire body if its immune defenses ever failed.