Usually antibiotic treatments do kill significant portion of bacterial flora. That's why antibiotics are typically followed by probiotic preparations to replen

Usually antibiotic treatments do kill significant portion of bacterial flora. That's why antibiotics are typically followed by probiotic preparations to replenish our bodies with "good" bacteria. This is not necessarily done to prevent us from dying of malnutrition. The bigger problem is that lacking "good" bacteria, we can have "bad" bacteria take over the void, causing even more problems.