Understanding the Female Reproductive Microbiome in Livestock

Understanding the Female Reproductive Microbiome in Livestock

For decades, techniques in Microbiology allowed researchers to study only a small proportion of microorganisms inhabiting a body site, due to techniques relying on culture of bacteria in selective media, thus neglecting species of bacteria that fail to grow under these conditions. Recent advances in genome sequence techniques allowed the study of all microorganisms present in a body site, making the study of microbiological systems more complete. The role of the microbiome in promoting homeostasis and protecting the host from disease is remarkable. Trillions of bacteria inhabit the intestinal tract of humans and provide metabolic pathways that are unique to bacteria, while mice raised in germ-free conditions have impaired anatomic compositions and physiologic functions. While the composition and function of the human reproductive microbiome is well defined, the reproductive microbiome in livestock greatly differs from humans, and its role on reproductive homeostasis and fertility is at an early stage.

The most studied species regarding the reproductive microbiome is the human. While the human vaginal microbiome is remarkably dominated by Lactobacillus species, which are correlated to fertility during in-vitro fertilisation and promote an acidic environment to protect the host from pathogenic bacteria, the human vaginal microbiome is unique within mammals. In bovines, for example, recent studies report a diverse reproductive microbiome, with little prevalence of bacteria from the genus Lactobacillus, and a near-neutral pH.

The goal of this Research Topic is to share information related to the reproductive microbiome in livestock species with an emphasis on fertility. Topics encouraged for this issue include, but are not limited to:

- Study commensal microorganisms in the reproductive microbiome of livestock species.
- Study the dynamic shifts in composition and function of the microbiome throughout the estrous cycle and in response to exogenous hormones often used in estrous synchronisation protocols, and the impacts on fertility.
- Identification of reproductive microbiome features related to fertility.
- Understand shifts in reproductive microbiome during the reproductive life of livestock species (during pregnancy, after parturition, at puberty onset, etc).
- Understand features of the reproductive microbiome on the composition of the offspring microbiome and postnatal performance.
- Understand the reproductive microbiome responses to semen exposure.
- Longitudinal studies aimed to investigate the dynamic changes in reproductive microbiome throughout an individual’s life.
- The impacts of host immunity on the reproductive microbiome.
- Features of the reproductive microbiome related to disease (i.e. endometritis, or related reproductive diseases).

Keywords: bovine microbiome, reproductive microbiome, commensal microbes, fertility, livestock