I dont really understand what your saying there Remi Sorry mate.
sorry, i'll clarify my comments a bit.
from a bacterial point of view, your blood is sterile- if it is not, you have septicaemia and are very sick in a hospital, or about to be. ditto if you have fungus/yeast/mould in your bloodstream- then you are really really sick and probably about to be dead. so in terms of anything in your blood contaminating/ ruining your beer...it won't happen.
in terms of blood borne viruses (HIV, Hep B, Hep C) etc, these are transferred by blood-blood contact, but not blood to oral contact (unless maybe you drank a very large volume of undiluted infected blood and had a gaping/bleeding mouth ulcer of your own in which contact could occur).
almost all of the nasties that make you spew and poo, are transmitted by faecal-oral transmission.
so...wash your hands after you go to the toilet, but bleed into your beer all you like.
hope that's not too much detail for anyone...
remi