WBM counts are suppressed and lineage balance is shifted with antibiotic therapy. (A) Bone marrow cells were counted on a hemocytometer in control (Ctrl) vs antibiotic-treated (Abx) mice. (B-G) Progenitor populations were quantified by flow cytometry in controls vs antibiotic-treated mice. (B) The percentage of total primitive progenitors (LSK) was determined by flow cytometry. Absolute numbers of (C) LSK progenitors, (D) hematopoietic stem cells, and (E) multipotent progenitor subsets, (F) common lymphoid progenitors, and (G) committed myeloid progenitor subsets are shown. Results are compiled from 4 independent experiments (n = 9-17 per group). Graphs show mean + SEM. Statistical significance was determined by Student t test or Mann-Whitney U test. *P < .05, **P < .01, ***P < .001, ****P < .0001.