The influence of experimental immunosupression on the condition of white laboratory mice genitourinary tract microbiocenosis is studied. Introduction of cyclophosphamide provokes GUT dysbiosis development, which manifests itself as changes of the ratio aerobes : anaerobes. So, it makes about 1:50 in the control group, it is close to 1:135 in the experimental group by the 15th day after completion of cyclophosphamide course, and it is about 1:195 by the 30th day.
An expected normalization of the mice GUT microbiocenosis condition after cessation of immunosuppressive factor action is not observed.