Table 1.

Summary of different categories of typical gut microbial pattern that can be found in healthy newborns.

	Gut characteristic bacterial populations in healthy newborns
Term neonates	Lactobacillus, Bifidobacterium
Preterm neonates	Enterobacteriaceae, Veillonella, Enterococcus, Staphylococcus
Breast feed	Lactobacillus, Bifidobacterium
Formula feed	Bacteroides, Staphylococcus, Clostridia, Enterococcus, Enterobacteria
Vaginally delivered	Prevotella, Lactobacillus
C-section	Corynebacterium, Staphylococcus, Propionibacterium

We report the principal variables that can affect the rising abundance of a population over another: the correspondence may concern either a genus (such as Staphylococcus), either a family (such as Enterobacteriaceae). It clearly shows that there's not a single typical healthy microbiota, but gut microbiota is rather a spectrum, result of all the combination of variables that coexist in an infant.