Since the discovery of the microbiome in humans, it has been studied in many mammalian species. Different microbiological communities with variable richness and diversity have been found among these species in distinct areas of the reproductive tract. Human studies have shown that the composition of the microbiome is dependent on body site and several host-related factors. Furthermore, specific phyla have been identified among the different species and within distinct areas of the female reproductive tract, but a “core” microbiome of the female reproductive tract has not been defined in any species. Moreover, the function of the microbiome in the reproductive tract is not yet fully understood. However, it has been suggested that a change in diversity of the microbiome and the presence or absence of specific microbial species might be useful indicators of pregnancy outcomes. Increased comprehensive knowledge of the microbiological communities in the female reproductive tract is needed since adverse outcomes represent a significant problem to many species, including livestock, exotic or endangered species, and humans. To the authors’ knowledge, a review combining current female reproductive tract microbiome data among different mammalian species has not been published yet. Herein is a comprehensive review of what is known in the field of the female reproductive microbiome and how it correlates with reproductive success or failure in mammals. Further studies may lead to optimization of therapies in the treatment of reproductive tract infections and pregnancy failure, and may create opportunities for novel approaches for improving reproductive efficiency in animals and people.

No abstract

Placenta is a pregnancy-specific organ responsible for maintenance of gestation and offspring survival in utero. Similar to other immune-privileged sites, fetoplacental unit was considered sterile. However, there is now strong evidence in humans that placenta harbors a unique microbiome. Although this work is in its infancy in veterinary medicine, there are accumulating metagenetic data to support the role of maternal reproductive tract microbiome in pregnancy success and adverse outcomes via placenta. This paper will review and highlight the emerging field of metagenetics in canine reproductive medicine. It will summarize what is known in humans, as well as veterinary species, with an emphasis on future metagenetic characterization of a canine placental microbiome and its potential role in pregnancy outcomes.

No abstract