The bowel, anyone would say, is the body in charge of the digestion and assimilation: its conformation to tube and its motility, in fact, enable it, thanks to enzymes, to break down ingested foods into their individual components (so-called nutrients), absorb them into the circulatory stream, and finally “push” unusable food residues so that they are eliminated in the form of feces.
The gut as an immune organ
Nothing to object to except for the fact that in this cursory overview another function no less important than those described has been omitted: the gut, in fact, is also an immune organ whose task is crucial in the early ages of life. Let us reflect for a moment: the absorbent mucosa, which in the adult individual has an area of as much as 400 square meters, can be considered on a par with the skin. Similarly to it, in fact, although it constitutes the inner lining of the intestine, it is constantly in contact with what comes from outside and thus plays a role as both a sentinel and a barrier.
The wall of the intestine, on the other hand, is rich not only in blood vessels, which receive nutrients and distribute them to all tissues of the body, but also in lymph vessels, where lymphocytes circulate. In fact, these particular highly specialized white blood cells, after forming in the bone marrow, need to be “trained” to perform their defensive task and find precisely in the digestive tract the optimal site for their break-in, also thanks to the presence of the bacterial flora.
A protection for the little ones
In the young child, then, let us not forget that the introduction of any new food is perceived as a potential aggression. In practice, the immune system cannot distinguish between a virus and a food protein, but thanks to special systems it develops what is known as tolerance: that is, it suppresses the mechanism by which contact with various foods would trigger the reaction underlying intolerance, namely the allergic response.
