There are two types of food poisoning: This is the case when you
consume food which is contaminated with some toxins, and those
are responsible for development of the poisoning symptoms. The
source organisms of these toxins might not be present anymore
(killed by heating during cooking, for example). In this case
there is no massive invasion of any foreign organisms into the
gut. This happens if you eat the food contaminated with
microorganisms, and these start to massively proliferate in your
alimentary system causing the symptoms of poisoning. The massive
intake of the bacteria (even 2-3 spoons of contaminated food
might contain millions of bacteria, like Staphilococcus in
contaminated diary products). In this case the balance of gut
microflora is dramatically changed due to introduction of a
considerable amount of foreign microorganisms. So, even the
poisoning seems to be "minor" (e.g., its symptoms are not so
dramatic), there could be different amounts of bacteria invading
the guts. The second important p