In addition to IgA, the infant is able to acquire some IgG from the milk.
There is a special receptor on infant gut cells (called FcRn for neonatal
Fc receptor) which binds IgG at low pH, protecting it and allowing it to
cross the epithelial barrier by an endocytic-like pathway. When it reaches
the basal side of gut cells, higher pH leads to release of the maternal IgG
into the bloodstream.
The same mechanism allows for transport of IgG from the mother to fetus
through the placenta, so that the baby is not born defenceless.
Regards,
Jean-Pierre
CC wrote:
> It is said that breast-feeding provide immunity to infants because breast
> milk contains antibodies.
> However, will the antibodies be digested by the infant when passing through
> the digestive tract?
> So, how does breast-milk provide immunity to infants?
>> Thanks
