Microbiota-based analysis reveals specific bacterial traits and a novel diagnostic strategy for infectious infertility

Background Tubal factor infertility (TFI) accounts for more than 30% of the cases of female infertility and mostly resides from an inflammatory process triggered by an infection. Clinical appearances largely differ, and very often infections are not recognized or remain completely asymptomatic over time. Here, we characterized the microbial pattern in females suffering from infectious infertility (ININF) in comparison to females with non-infectious infertility (nININF), female sex workers (FSW) and healthy controls (fertile).Results Females with infectious infertility differed significantly in the seroprevalence of IgG antibodies against the C. trachomatis proteins MOMP, OMP2, CPAF and HSP60 when compared to fertile females. Microbiota analysis through 16S rRNA gene- sequencing of cervical swabs revealed significant differences between ININF and fertile controls in the relative abundance of Gardnerella (9.55 % vs. 5.31 %). Alpha diversity varies among groups, which are characterized by community state types including Lactobacillus-dominated communities in fertile females, an increase in diversity in all the other groups and Gardnerella-dominated communities occurring more often in ININF.Conclusions While all single parameters did not allow predicting infections as the cause of infertility, including C. trachomatis IgG/IgA status together with 16S rRNA gene analysis of the ten most frequent taxa a total of 93.8% of the females were correctly classified. Further studies are needed to unravel the impact of the cervical microbiota in infectious infertility and its potential for optimizing diagnostic algorithms.