Escherichia coli (E. coli) is a gram negative bacterium assigned to the Enterobacter family. E. coli comprises various bacterial species and subspecies, some being common colonisers of the human intestine, others being pathogenic, e.g. enteropathogenic E. coli (EPEC). E. coli is an initial coloniser of the gut after birth, predominately colonising the large intestine and adapted its metabolism to this environment (Secher et al. 2016).