The count of live bacteria in products containing these bacteria is in the millions and billions daily per dose. There has been some question as to whether these bacteria are killed by the acidic stomach juices, but when taken in sufficient quantities, some organisms do make it down to the colon. I believe that these bacteria should not be taken regularly, but rather in specific courses to repopulate the colon with these "friendly" bacteria after antibiotic use or to treat intestinal yeast overgrowth; otherwise, I recommend them for one to two weeks once or twice a year, or when traveling to underdeveloped countries with higher risks of intestinal contamination from infectious organisms, for which the acidophilus bacteria offer some protection.