Comparative analysis of the testicular and uretral microbiota in azoospermia patients using next generation sequencing (NGS)

Aim. To determine the role of taxonomic bacterial diversity of the urethral and testicular microbiota in the development of male infertility using high-throughput next-generation sequencing (NGS).Material and methods. In the period between 2018 and 2022 we examined 53 patients. Three study groups were formed: Infertile patients with nonobstructive azoospermia and concomitant varicocele (n = 13) – group 1; Infertile patients with obstructive azoospermia (n = 29) – group 2; Fertile patients with confirmed paternity and testicular pathology requiring histological verification to exclude testicular oncopathology (n = 11) – group 3. Each patient underwent TESE with testicular both and urethral tissue sampling in order to compare the bacterial landscape and control the purity of the method. The obtained material was sequenced using a high-throughput method (NGS).Results.According to our findings, the testicular tissue of obstructive azoospermia patients had significantly depleted bacterial diversity in comparison to nonobstructive azoospermia and concomitant varicocele ones. Also, the fertile group turned out to be the most diverse in its taxonomic community. These results may suggest the bacterial microbiome’s influence on men’s reproductive health.Discussion.Our urogenital bacterial diversity analysis showed that human testicular tissue is not a microbiologically sterile environment and also presented new data associated with testicular tissue and its possible relations with male infertility.Conclusion. A focus on the qualitative and quantitative composition of the testicular microbial community may form the new basis in the diagnosis and treatment of male infertility associated with various types of azoospermia