A transcriptomic insight into the human sperm microbiome through next-generation sequencing.

Area of Science:

• Microbiology
• Genomics
• Reproductive Biology

Background:

• The human sperm microbiome remains largely unexplored.
• Understanding its composition is crucial for male reproductive health.

Purpose of the Study:

• To characterize the viral and bacterial RNA cargo in human sperm using Next Generation Sequencing (NGS).
• To identify potential microbiome patterns within sperm samples from healthy fertile donors.

Main Methods:

• RNA sequencing (RNA-seq) of poly(A) RNA from 12 human sperm samples.
• Alignment to microbiome databases using GAIA software for quantification of Operational Taxonomic Units (OTU).
• Hierarchical Cluster Analysis (HCA) and Principal Component Analysis (PCA) to identify microbiome patterns.

Main Results:

• Sixteen microbiome categories (viral and bacterial) exceeded the expression threshold.
• Viruses constituted 23.07% OTU and bacteria 2.77% OTU.
• The Herperviriales order and Escherichia coli were the most abundant viral and bacterial taxa, respectively.
• Four distinct sample clusters with unique microbiome fingerprints were identified.

Conclusions:

• This pilot study provides novel insights into the human sperm microbiome composition.
• Significant variability exists, but common microbiome patterns were observed among individuals.
• Further standardized NGS studies are needed to fully understand the semen microbiome and its role in male fertility.