Composition and diversity of fecal microbiota in W/W and wild-type mice. (A) Relative abundance of Streptococcus in human fecal microbiota from healthy donors (HD, n = 23) and patients with pRD (n = 15). Significance was determined by a Kruskal–Wallis chi-squared test. (B) Principal coordinate plots show beta diversity using the Bray–Curtis metric of fecal microbiota from wild-type (+/+) or Rag1^w/w (W/W) mice collected from isolated mice at 3 and 14 wk of age (n = 5/group). (C) Top 10 differentially abundant genus in the fecal microbiota of +/+ or W/W mice collected from isolated mice at 14 wk of age (n = 5/group). Significance was computed from the linear mixed-effects model ∼Group + (1|SubjectID) using the MaASLin2 R package. (D) Relative abundance of Intestinimonas genus, Lachnospiraceae genus, and Oscillibacter genus in the fecal microbiota of +/+ or W/W mice collected from isolated mice at 3, 5, 10, and 14 wk of age (n = 5/group). Significance was computed from the linear mixed-effects model ∼Group + (1|SubjectID) using the MaASLin2 R package. Data are from at least two independent experiments. **P < 0.01. HD, healthy donors.