Intermittent Lactobacilli-containing Vaginal Probiotic or Metronidazole Use to Prevent Bacterial Vaginosis Recurrence: A Pilot Study Incorporating Microscopy and Sequencing

Abstract

Bacterial vaginosis (BV) is associated with HIV acquisition and adverse pregnancy outcomes. Recurrence after metronidazole treatment is high. HIV-negative, non-pregnant Rwandan BV patients were randomized to four groups (n = 17/group) after seven-day oral metronidazole treatment: behavioral counseling only (control), or counseling plus intermittent use of oral metronidazole, Ecologic Femi+ vaginal capsule (containing multiple Lactobacillus and one Bifidobacterium species), or Gynophilus LP vaginal tablet (L. rhamnosus 35) for two months. Vaginal microbiota assessments at all visits included Gram stain Nugent scoring and 16S rRNA gene qPCR and HiSeq sequencing. All interventions were safe. BV (Nugent 7-10) incidence was 10.18 per person-year at risk in the control group, and lower in the metronidazole (1.41/person-year; p = 0.004), Ecologic Femi+ (3.58/person-year; p = 0.043), and Gynophilus LP groups (5.36/person-year; p = 0.220). In mixed effects models adjusted for hormonal contraception/pregnancy, sexual risk-taking, and age, metronidazole and Ecologic Femi+ users, each compared to controls, had higher Lactobacillus and lower BV-anaerobes estimated concentrations and/ or relative abundances, and were less likely to have a dysbiotic vaginal microbiota type by sequencing. Inter-individual variability was high and effects disappeared soon after intervention cessation. Lactobacilli-based vaginal probiotics warrant further evaluation because, in contrast to antibiotics, they are not expected to negatively affect gut microbiota or cause antimicrobial resistance.Most women have a vaginal microbiota (VMB) that consists predominantly of lactobacilli 1 . The most common type of vaginal dysbiosis is bacterial vaginosis (BV), characterized by a decrease in lactobacilli and increase in fastidious anaerobes 2 . Other types of bacterial dysbiosis, vulvovaginal candidiasis, and Trichomonas vaginalis (TV) are also common. These conditions are associated with vaginal inflammation, thereby increasing the risk of HIV acquisition 3 . BV is also associated with pelvic inflammatory disease, infertility, and adverse pregnancy outcomes 2 .The majority of women seeking care for vaginal symptoms receive antibiotic or antifungal treatment empirically or syndromically without any diagnostic testing 4 . In some specialized clinics, women might be offered www.nature.com/scientificreports www.nature.com/scientificreports/ limited diagnostic testing, such as vaginal pH determination and/or wet mount microscopy. In research settings, BV is typically diagnosed by the Amsel criteria or Nugent scoring 5,6 , with the latter currently being considered the gold standard: Gram-stained vaginal smears are scored based on microscopic visualization of three bacterial morphotypes with a score of 0-3 considered normal, 4-6 intermediate, and 7-10 BV regardless of symptoms. In the last 15 years, molecular methods have become more widely available, and have been applied to the VMB, although mostly in descriptive studies to date 1 .Evidence is mounting that 'm...

Pathobionts in the Vaginal Microbiota: Individual Participant Data Meta-Analysis of Three Sequencing Studies

“…The BactQuant 16S rRNA gene qPCR (Liu et al, 2012) was only done in the Rwanda VMB study (N = 379, of which 158 samples were not influenced by the interventions). The 16S rRNA gene concentration per sample was used to convert the relative abundances of that sample into estimated concentrations as previously described (van de Wijgert et al, 2020a). We used both relative abundances as well as estimated concentrations for the Rwanda VMB study, but only had relative abundances for the other two studies.…”

“…The Rwanda VMB study screened HIV-negative, nonpregnant, pre-menopausal women at high risk of sexually transmitted infections (STIs) for BV (van de Wijgert et al, 2020a). Women with BV were treated with metronidazole for seven days, and when cured of BV and other urogenital infections, were randomized to no intervention, or intermittent use of oral metronidazole or two different lactobacilli-containing vaginal probiotics for 2 months.…”

Vaginal microbiota and the potential of Lactobacillus derivatives in maintaining vaginal health

“…In addition, L. rhamnosus BMX 54 also showed its potential to be used as adjuvant treatment in reshaping vaginal microbiota and by reducing BV recurrence after six to nine months of treatment [ 171 ]. Recent evidence showed that intermittent application of vaginal capsule (containing Lactobacillus acidophilus W70, Lactobacillus brevis W63, Lactobacillus helveticus W74, Lactobacillus plantarum W21, Lactobacillus salivarius W24, and Bifidobacterium bifidum W28) restored Lactobacillus -dominated vaginal microbiota and significantly reduced risk of BV incidence by 2.8-fold as compared to non-treated control group (10.18 per person-year) [ 172 ]. Meanwhile, the usage of lactobacilli could also reduce the rate of VVC recurrence.…”

Vaginal probiotic adherence and acceptability in Rwandan women with high sexual risk participating in a pilot randomised controlled trial: a mixed-methods approach

“…Product efficacies were not known during the trial, and the efficacy results of the pilot trial are reported elsewhere. 17 Briefly, the vaginal probiotics did improve the vaginal environment (increased lactobacilli and reduced BV-associated bacteria) compared with counselling only, but not as much as oral metronidazole did.…”

“…Other clinical exclusion criteria were applied but were rare. 17 Women were recruited by study staff with the assistance of Community Mobilisers who had strong ties with local high-risk women (particularly sex workers). study products and dosing Ecologic Femi+ (EF+; Winclove Probiotics, Amsterdam, Netherlands) is a vaginal capsule containing lyophilised lactic acid-producing bacteria.…”