The Importance of Normal Colonization of the Newborn in Immune Development and Prevention of Disease

Why is the colonization of the newborn’s gut with healthy bacteria important?

The colonizing bacteria have a profound impact on gastrointestinal function, as well as the immune function.  It is particularly important at the initial stage of colonization because this is when the infant is developing defences against bacteria plus the prevention of immune related disease.

Which factors are key for optimal colonization – is it the pregnancy or is it the type of delivery?

The delivery is very important, because this is where the infant gets most of its bacteria.  Being born naturally via vaginal delivery offers the best defence.    It is true that if the pregnancy has not been a healthy one, perhaps where the mother puts on too much weight, the infant might be exposed to the wrong type of bacteria during delivery.

What happens if antibiotics are given to the newborn?

While we don’t know one hundred percent, antibiotics are probably disrupting the colonization process which is very important in a window of time for the infant to develop defence.

Over the past 50 to 80 years we have seen a gradual shift in disease patterns globally, with less infectious disease and more immune disease and allergy problems.  Is this connected to colonization?

Yes, I think so.  In the absence of normal colonization with the use of probiotics or delivery by caesarian section, the bacteria do not develop properly, so they cannot influence the immune function of the infant.  Therefore, the infant is more likely to develop immune related problems.

So, could that mean that the wrong bacteria is introduced and more allergies develop?  What can we do about that?

We can make sure we optimize colonization.  Do not use probiotics.  Try to use natural delivery.  Make sure the mother’s pregnancy is healthy.  If these goals have not been met, studies have shown that probiotics given to the infant during this important window of time might have an impact on preventing allergic immune reactions.