Figure 2.

Schematic representation of the gut phage community development with age. Individuals are colonized early after birth, within 0–4 days after birth (DOB). During the first days of life, the diversity of the phage community is high and the microbial community abundance and diversity is low [51]. A reduction in Caudovirales diversity leads to an expansion and a shift in the microbial community composition and an increase in Microviridae phage diversity and abundance. A relatively stable phage community is maintained during the adult life. Changes in the phage community associated with a shift towards an elderly-like microbial community are unknown.