Vaginal microbiome following orally administered probiotic

Abstract

Here, we present a longitudinal shotgun sequencing metagenomics study of 16 healthy, Danish women in the reproductive age. The aim of the study was to investigate whether lactobacilli, orally consumed, had any impact on the vaginal microbiome and its functional potential. The 16 women aged 19-45 years were recruited from Copenhagen, Denmark. One baseline vaginal sample (Day 0) and two study samples (Days 25-30 and Days 55-60, respectively), were sampled. The vaginal samples were analyzed by shotgun metagenomics. We detected 26 species in the vaginal microbiota of the 16 women, of which six belonged to the Lactobacillus genus. We observed three vaginal microbiome clusters mainly dominated by Gardnerella vaginalis, Lactobacillus iners, or Lactobacillus crispatus. The oral probiotic had no detectable effect on either the composition or the functional potential of the vaginal microbiota. Most of the study subjects (11 out of 16 women) exhibited only minor changes in the vaginal microbiome during the treatment with probiotics. Any compositional changes could not be associated to the probiotic treatment. Future studies may benefit from an increased number of participants, and administration of the probiotics during conditions with bacterial imbalance (e.g., during/after antibiotic treatment) or the use of different Lactobacillus spp. known to colonize the vagina.

Keywords: Vaginal microbiome; healthy microbiome; public health; shotgun metagenomics; women.

Fig. 1

MGS abundance profiles of the top‐10 most dominant MGSs in the study vaginal samples. The samples are clustered based on Bray–Curtis dissimilarity and a phylogenetic tree on top of the plot exhibits the different species clusters. Bars do not sum to 100% because we represent only the 10 most dominant species across samples, and because some reads mapped to non‐MGS‐annotated genes.

Fig. 2

Vaginal samples. PCoA based on Bray–Curtis dissimilarities between vaginal samples calculated using the MGS abundances in vaginal samples. Numbers denote the subject, and the samples are color coded by visit. The median, of all the samples per visit, is expressed with a larger dot (centroid).