Differential vaginal Lactobacillus species metabolism of glucose, L and D-lactate by 13C-nuclear magnetic resonance spectroscopy

Introduction: Cervicovaginal dysbiosis can lead to infection-associated spontaneous preterm birth. Objective: To determine whether vaginal Lactobacillus species, L. crispatus and L. jensenii, differentially metabolise glucose, L- and/or D-lactate to propagate their survival/dominance. Methods: Bacteria were incubated anaerobically for 24h at 37°C, with 13Cu-glucose, 13C3-D-lactate or 13C3-L-lactate (singularly or combined) for 24h. 13C-spectra were acquired using a 9.4T NMR spectrometer. Results: L. crispatus and L. jensenii (n=6 each) metabolised 13C-glucose to 13C-lactate and 13C-acetate. L. jensenii converted more 13C3-D- or 13C3-L-lactate to 13C-acetate than L. crispatus, p<0.001. Conclusion: Conversion of glucose and lactate to acetate by L. jensenii compared to L. crispatus, suggests a possibly important pathomechanism of dysbiosis and infection-associated spontaneous preterm birth.