FIG 2.

Twin pair A/B and Y/Z bacterial community profiles. Fecal samples from two pairs of twins were profiled from week 1 to week 8 (twin pair A/B) or week 9 (twin pair Y/Z) after birth. Twins A and B were admitted to a NICU in a different hospital than twins Y and Z. Samples were obtained during the week indicated on the x axis. Results are shown for each sample as a “100% stacked column,” with the y axis box size indicating the percentage of the total sequences. Pink triangles at the top indicate antibiotic treatment prior to sample collection. The following specific taxa are highlighted with the indicated colored borders: Enterobacter cloacae, Klebsiella pneumoniae, E. coli taxa, Bifidobacterium longum, and Clostridium difficile.