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.

Leónides Fernández,Claudio Alba,David Beltrán,Juan M Rodríguez,Irma Castro,Rebeca Arroyo

doi:10.3390/nu13010162

Leónides Fernández, Claudio Alba + Show 4 more

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https://doi.org/10.3390/nu13010162

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Abstract

In this study, the cervicovaginal environment of women with reproductive failure (repetitive abortion, infertility of unknown origin) was assessed and compared to that of healthy fertile women. Subsequently, the ability of Ligilactobacillus salivarius CECT5713 to increase pregnancy rates in women with reproductive failure was evaluated. Vaginal pH and Nugent score were higher in women with reproductive failure than in fertile women. The opposite was observed regarding the immune factors TGF-β 1, TFG-β 2, and VEFG. Lactobacilli were detected at a higher frequency and concentration in fertile women than in women with repetitive abortion or infertility. The metataxonomic study revealed that vaginal samples from fertile women were characterized by the high abundance of Lactobacillus sequences, while DNA from this genus was practically absent in one third of samples from women with reproductive failure. Daily oral administration of L. salivarius CECT5713 (~9 log10 CFU/day) to women with reproductive failure for a maximum of 6 months resulted in an overall successful pregnancy rate of 56%. The probiotic intervention modified key microbiological, biochemical, and immunological parameters in women who got pregnant. In conclusion, L. salivarius CECT5713 has proved to be a good candidate to improve reproductive success in women with reproductive failure.

Highlights

Increasing evidence has highlighted the relevance of the microbiota of the female genital tract for human reproduction [1,2]
L. salivarius CECT5713 showed inhibitory antimicrobial activity against all the G. vaginalis, S. agalactiae, C. albicans, C. glabrata, C. parapsilosis, and U. urealyticum strains used as indicators in this study
Co-aggregation was intense with G. vaginalis, S. agalactiae, and C. albicans strains

Summary

Introduction

Increasing evidence has highlighted the relevance of the microbiota of the female genital tract for human reproduction [1,2]. The bacterial communities of 396 asymptomatic women were classified into five distinct vaginotypes; four of them were dominated by Lactobacillus crispatus, Lactobacillus gasseri, Lactobacillus iners, and Lactobacillus jensenii, respectively; in contrast, the fifth one had lower proportions of lactobacilli and was predominantly composed of strictly anaerobic bacterial genera, such as Gardnerella, Prevotella, Megasphaera, Atopobium, or Dialister [3]. This last vaginotype was associated to high Nugent scores, a Gram-staining based technique used for the diagnosis of bacterial vaginosis (BV)

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