Making inroads into improving treatment of bacterial vaginosis - striving for long-term cure

Abstract

Bacterial vaginosis (BV) is one of the great enigmas in women's health, a common condition of unknown aetiology, which is associated with significant morbidity and unacceptably high recurrence rates. While it remains unclear whether BV recurrence is predominantly due to failure of current antibiotic regimens to eradicate BV-associated bacteria (BVAB) and biofilm, a failure of some women to re-establish a resilient Lactobacillus-dominant vaginal microbiota, reinfection from sexual partners, or a combination of these factors, it is inherently challenging to make significant inroads towards this goal. In this review, we will outline why BV is such a clinical and epidemiologic conundrum, and focus on several key approaches that we believe merit discussion and clinical research, including strategies to: i) prevent reinfection (partner treatment trials), ii) boost favourable vaginal Lactobacillus species and promote a Lactobacillus-dominant vaginal microbiome (hormonal contraceptive and probiotic trials) and iii) disrupt vaginal BV-associated biofilm.

Fig. 1

BV recurrence and potential therapeutic strategies

Fig. 2

Heatmap showing the distribution of bacterial taxa found in the vaginal microbial communities of 394 reproductive-age women in the U.S. Adapted with permission from Proceedings of the National Academy of Sciences of the United States of America [70]

Fig. 3

Daily temporal dynamics of vaginal bacterial communities in six women over a 10-week period. The relative abundance of each bacterial taxa is depicted as interpolated bar graphs. The bacterial taxa are indicated on the right of each bar graph with color codes. Daily Nugent Gram stain scores (range 0–10) and pH (range 4–7) are indicated below the graph. Red solid circles represent menstruation. Missing pH values are indicated by red box, otherwise pH is in line with a value of 4. Missing Nugent scores are also indicated by the red box, otherwise the score is in line with 0. The figure illustrates that the top four participants (a, b, c, d) carry highly stable communities dominated by L. crispatus (a), L. iners (b) and non-Lactobacillus dominated communities (c and d). Women e and f experienced unstable communities with both high Nugent scores and pH. Adapted with permission from Microbiome [78]

Fig. 4

Meta-analysis of hormonal contraception and prevalent BV. Figure first published in PLoS One [93]

Fig. 5

Meta-analysis of hormonal contraception and incident BV. Figure first published in PLoS One [93]