Detection of Human Y Chromosome and the SRY Gene in Fecal Samples of Female Patients Following Fecal Microbiota Transplantation

Abstract

Background and Aims

We have postulated that fecal microbiota transplantation (FMT) is associated with transfer of microbiota from the donor and engraftment of intestinal epithelial cells in the recipient’s colonic mucosa enabling the restoration of a stable microbial environment.

Methods

We analyzed the presence of human Y chromosome (ChrY) and sex-determining region Y (SRY) gene within total human DNA extracted from fecal samples collected from 30 donors and 22 recurrent Clostridium difficile infection (RCDI) patients before and up to 24 months after FMT. A next-generation sequencing data analysis pipeline was applied to quantify the percentage of reads aligning to human ChrY. SRY gene detection was also performed by quantitative polymerase chain reaction and droplet digital polymerase chain reaction.

Results

A significantly higher percentage of ChrY reads were identified in fecal samples of male donors as compared to female donor (P < .0001). Fecal samples collected from female RCDI patients who received FMT from male donors showed a significantly (P < .05) higher percentage of ChrY reads compared to female samples without male FMT donors. Four female patients with RCDI who received FMT from male donors showed a very large percent ChrY increase post-FMT even several months after FMT. SRY gene signal was detected by droplet digital polymerase chain reaction in 7 of the 11 fecal samples collected from the male donor pool but none from the female pool.

Conclusion

These observations clearly demonstrate the presence of ChrY and SRY gene signal in stool samples collected from male patients. The presence of increased ChrY in the stool samples of female RCDI patients after FMT from a male donor suggests possible engraftment of exfoliated intestinal epithelial cells in a subset of these patients.