Microbiota increase MPPs and regulate their differentiation toward the myeloid lineage. (A) Numbers of LSK cells and further separation of HSPCs into HSC, ST-HSC, HPC-2, and MPP cells in the BM of SPF, GF, and CoH-GF mice (n = 10-14). Each circle represents an individual mouse. (B) Relative expression of genes related to each lineage differentiation in the MPP population. Data are presented as log₂ fold changes in mRNA levels measured by reverse-transcription quantitative polymerase chain reaction (GF/SPF and CoH-GF/SPF) with cells pooled from 6 to 8 mice per group. Data are pooled from 2 independent experiments (A) and are representative of 2 independent experiment with similar results (B). Data are mean ± standard error of the mean. *P < .05, **P < .01, ***P < .001, 1-way ANOVA with Bonferroni multiple comparison. E/MegE, erythroid/megakaryocytic-erythroid; Lympho, lymphoid; Myelo, myeloid.