Fecal microbiota transplantation (FMT) is prescribed to treat various gastrointestinal pathologies. One of the most important and significant stages of FMT is selection of the donor. In recent years, special attention has been paid to checking the biomaterial for genes marking resistance to various groups of antibiotics. This study aimed to analyze the occurrence of mef and ermB drug resistance genetic markers in population of various age groups, including breastfed infants, and to determine microbiological composition of the flora of distal part of the intestine of potentially healthy volunteering FMT donors. A total of 52 biological samples (46 stool samples and 6 breast milk samples) were analyzed by real-time polymerase chain reaction. The macrolides resistance gene (mef) was detected in 97.8% of stool samples (different age groups), the gene marking resistance to macrolides, lincosamides, streptogramin (ermB) — in 93.5%. In the isolated "mother-child" group, the mef gene was found in all samples of breast milk and feces. The ermB gene in this group was found in 3 out of 6 breast milk samples and 4 out of 6 infant stool samples. Since the mef and ermB genetic determinants were identified not only among in adults but also in infants, it was suggested that transplant material (feces) containing these genes can be used for FMT. The analysis of microbiological composition of stool samples from 23 healthy volunteers (potential FMT donors) revealed that it rarely (in 8.7% of cases only) corresponds to what is considered to be a normal microbiota of the intestine's distal part.