Is there good bacteria

Answer 1

Yes we would not survive without the good bacteria. Most of our surfaces are covered with good or neutral bacteria - in case they are eliminated e.g. by antibiotics or too much wash the bad bugs jump on the site to make their evil deeds.

An example is the vagina, with in normally populated with good lactic acid bacteria. Only when they stop dominating, other organisms take over at the woman may acquire bacterial vaginosis or thrush