Changes in microbiome diversity and abundance. (A) Nonsignificant change in species diversity of both feeding groups from baseline to periengraftment (adjusted LMER; P = .93). (B) Change in relative abundance of Lactobacillus_C between groups over time (adjusted LMER; P = .013). (C) Change in relative abundance of Lactobacillus_C rhamnosus between groups over time (adjusted LMER; P = .022). (D) Change in the relative abundance of Lactobacillus_Cparacasei between groups over time (adjusted LMER; P = .026). (E) Change in relative abundance of Faecalicatena gnavus between groups over time (adjusted LMER; P = .0027). (F) The relative abundance of Bifidobacterium in the prebiotic and standard groups at the periengraftment timepoint (adjusted ANOVA; P = .65). Rel., relative.