Broad scope method for creating humanized animal models for animal health and disease research through antibiotic treatment and human fecal transfer

Traditionally, mouse humanization studies have used human fecal transfer to germ-free animals. This practice requires gnotobiotic facilities and is restricted to gnotobiotic mouse lines, which limits humanized mouse research. We have developed a generalizable method to humanize non germ-free mice using antibiotic treatment and human fecal transfer. The method involves depleting resident intestinal microbiota with broad-spectrum antibiotics, introducing human microbiota from frozen fecal samples by weekly gavage, and maintaining mice in HEPA-filtered microisolator cages. Pyrosequencing cecal microbiota 165 rRNA genes showed that recipient mice adopt a humanized microbiota profile analogous to their human donors, and distinct from mice treated with only antibiotics (no fecal transfer) or untreated control mice. In the humanized mice, 75% of the sequence mass was observed in their respective human donor and conversely, 68% of the donor sequence mass was recovered in the recipient mice. Principal component analyses of GC- and HPLC-separated cecal metabolites were performed to determine effects of transplanted microbiota on the metabolome. Cecal metabolite profiles of mice treated with only antibiotics (no fecal transfer) and control mice were dissimilar from each other and from humanized mice. Metabolite profiles for mice humanized from different donor samples clustered near each other, yet were sufficiently distinct that separate clusters were apparent for each donor. Also, cecal concentrations of 57 metabolites were significantly different between humanization treatments. These data demonstrate that our protocol can be used to humanize non germ-free mice and is sufficiently robust to generate metabolomic differences between mice humanized from different human donors.