And the other big aspect to all this is what probiotics the baby or child has in their system.
Children born by cesarean section or ever having had antibiotics (including through the mother) have none, so are first in line to develop conditions like asthma and autism if injected with a bunch of dangerous toxins.
http://www.drperlmutter.com/about/brain-maker-by-david-perlmutter-md/
