Comparative Metabolomic Analysis of Vaginal Microbiota in Planktonic and Biofilm States Unveils Species-Specific Metabolic Signatures

Abstract

Bacterial vaginosis (BV) affects approximately 29% of women in the U.S., with higher rates among certain demographics and up to 50% recurrence within a year. Besides complications like increased risk of sexually transmitted infections (STIs), pregnancy-related issues, it can negatively impact psychological well-being, leading to discomfort and reduced quality of life. While previous studies have provided insights into the overall metabolomic profile of healthy and diseased vaginal environments, the elucidation of individual microbial metabolite signatures remains limited. Furthermore, given that biofilms exhibit distinct metabolic requirements compared to planktonic cultures, a differential analysis of metabolites in both growth conditions could reveal potential therapeutic targets. This study presents a comprehensive metabolomic analysis and comparison of significant vaginal microbes including Lactobacillus crispatus, Gardenerella vaginalis, and Lactobacillus iners in both planktonic and biofilm growth conditions. Our analysis revealed distinct metabolite production and consumption patterns among different microbes and growth modes. In biofilm cultures, metabolite consumption is influenced by nutrient availability, which in turn regulates the profile of produced metabolites. G. vaginalis demonstrated the ability to form biofilms in various media types. Limited shared metabolic pathways in both biofilm types of G. vaginalis, highlights the unique metabolic processes involved in their formation. Despite L. crispatus suspension and biofilm cultures sharing 142 consumed and 104 produced metabolites, the biofilm culture demonstrated a remarkable metabolic shift. While comparing suspension and biofilm cultures of L. crispatus, L. iners, and G. vaginalis, we found convergence in nutrient utilization, but divergence in metabolic outputs reflecting growth-specific adaptations and underscore the importance of considering the state of existence when studying the vaginal microbiome. This study provides valuable insights into the growth mode-specific metabolic requirements of key vaginal microbes. The findings underscore the potential for leveraging metabolite-mediated microbial cross-talk as a novel therapeutic approach against BV. This avenue of research warrants further investigation, as it could lead to the development of targeted interventions that modulate the vaginal microbiome through metabolic manipulation, potentially offering more effective and personalized treatments for BV.