Microbiota and Human Reproduction: The Case of Female Infertility.

Iolanda Veneruso,Federica Cariati,Rossella Tomaiuolo,Valeria D’Argenio

doi:10.3390/ht9020012

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.

Highlights

The availability of highly sensitive technologies, i.e., next-generation sequencing, for the in-depth study of microbial communities’ composition and richness, has prompted the interest into metagenomics
As for other body sites, this resident microbiota has been involved in the maintenance of a healthy status
The Human Microbiome Project has assessed that the vaginal microbiota accounts for about 9% of the whole human microbiota [5,6,7]

Summary

Introduction

The availability of highly sensitive technologies, i.e., next-generation sequencing, for the in-depth study of microbial communities’ composition and richness, has prompted the interest into metagenomics. Lactobacilli have been reported as the most represented bacteria in this body site, other represented genera being Prevotella, Bifidobacterium, Gardnerella, Atopobium, Megasphaera, Sneathia, and Anaerococcus [5,6,7]. These bacteria have been implicated in different phases of reproduction from gamete formation, fertilization, pregnancy establishment and maintenance, and in the microbial colonization of the fetus and/or of the newborn [3,4,8]. Many efforts have been made to try to establish the composition and role of the “healthy” female reproductive system microbiome, and the effects of a dysbiosis on human reproduction and fertility [4,8]

Objectives

Methods

Findings

Conclusion