Microbiota and Human Reproduction: The Case of Female Infertility

Abstract

During the last decade, the availability of next-generation sequencing-based approaches has revealed the presence of microbial communities in almost all the human body, including the reproductive tract. As for other body sites, this resident microbiota has been involved in the maintenance of a healthy status. As a consequence, alterations due to internal or external factors may lead to microbial dysbiosis and to the development of pathologies. Female reproductive microbiota has also been suggested to affect infertility, and it may play a key role in the success of assisted reproductive technologies, such as embryo implantation and pregnancy care. While the vaginal microbiota is well described, the uterine microbiota is underexplored. This could be due to technical issues, as the uterus is a low biomass environment. Here, we review the state of the art regarding the role of the female reproductive system microbiota in women’s health and human reproduction, highlighting its contribution to infertility.

Application of Ligilactobacillus salivarius CECT5713 to Achieve Term Pregnancies in Women with Repetitive Abortion or Infertility of Unknown Origin by Microbiological and Immunological Modulation of the Vaginal Ecosystem

“…Our study has some limitations. First, the microbiota of the genitourinary tract of the partner was not evaluated and some studies have shown that male microbiota may also play a fundamental role in reproductive outcomes [132,133]. In fact, the couple (when applicable) should be considered as a single entity to achieve the best reproductive outcomes [134].…”

Unraveling the Balance between Genes, Microbes, Lifestyle and the Environment to Improve Healthy Reproduction

“…In this scenario, a role of the microbiota in human reproduction has emerged [ 71 , 72 ]. In particular, the semen microbiota composition has been related to altered sperm cells motility, hyperviscosity, oligoasthenoteratozoospermia, and/or sperm DNA fragmentation [ 73 , 74 , 75 ].…”

Microbiota and Human Reproduction: The Case of Male Infertility

“… Individual variability factors affecting semen microbiota composition and processes in which semen microbiota has been suggested to play a role [ 12 , 19 , 21 , 23 , 36 , 49 , 55 , 56 , 57 , 58 , 63 ]. The simultaneous evaluation of the female partner’s microbiota should be taken into account considering their mutual influences and the potential effects on couples’ and offspring health [ 64 ]. …”