Table 1.

Main factors and phases of early microbial imprinting.

(1) Prenatal (colonization with vertically transferred microbial material)

(2) Delivery (cesarean section versus natural)

(3) Feeding (human milk versus formula milk)

(4) Infections

(5) Antibiotics

(6) Intestinal environment (cystic fibrosis, short gut, celiac disease)