There's something unique about garlic among germ fighters, which probably explains its esteem and long history of use. Some people say lots of it will kill off good bacteria, but I think it's a matter of adjusting the dose. If done right, in the upper GI tract it's a potent anti-"..everything," but that potency wears off as it travels downstream so that by the time it gets to the lg. intestine its fibers are able to feed the good flora.