Feasibility study on construction of humanized mice with antibiotics combined with fecal bacteria transplantation

Objective: To select a common method of humanized mice and verify its feasibility with the aim to provide atheoretical basis for subsequent fecal bacteria transplantation research. Methods: 1. Specific Pathogen Free (SPF) mice were fed with antibiotics mixed with sterilized drinking water for 3 weeks, during which the general situation of mice was recorded. After 3 weeks, the number of microbes in mice's feces was evaluated by Gram staining. 2. After antibiotic treatment, mice were transplanted fecal bacteria by gavage for a week. Then, the contents of fecal bacteria in the donor and recipient feces was determined by RT-PCR, to evaluate the colonization effect of fecal bacteria. Results:（1）Antibiotic treatment had an effect on weight, feed and drinking water consumption of mice, and the fecal bacteria in mice decreased obviously.（2）After fecal bacteria transplantation, the Firmicutes, Bacteroidetes and Firmicutes/ Bacteroidetes of the mice receiving Donor1 fecal bacteria accounted for 15.4%, 112% and 13.7% of the mice receiving Donor2 fecal bacteria, respectively. The Firmicutes, Bacteroidetes and Firmicutes/Bacteroidetes of Donor1 fecal bacteria accounted for 33.7%, 104% and 32% of Donor2, respectively. The recipient's gut microbes had the same trend as human donors. Conclusions: These results indicate that antibiotic treatment combined with fecal bacterial transplantation is feasible and safe for humanizing SPF mice.