Proceedings of The Physiological Society

Europhysiology 2018 (London, UK) (2018) Proc Physiol Soc 41, C064

Oral Communications

Ethnic differences in the pregnant vaginal environment, host response and risk of spontaneous preterm birth

R. M. Tribe1, T. Kanno1, E. Prosdocimi2, N. Hezelgrave1, E. Chin-Smith1, V. Mistry1, A. H. Shennan1, A. J. Mason3

1. Women and Children's Health, King's College London, London, Please Select, United Kingdom. 2. Centre for Host-Microbiome Interactions, King's College London, London, Please Select, United Kingdom. 3. Institute of Pharmaceutical Science, School of Cancer & Pharmaceutical Sciences, King's College London, London, United Kingdom.

Introduction: We reported inflammation in the female reproductive tract (14-18 weeks') of women at higher risk of spontaneous preterm birth (sPTB) [1-2]. The driver for this innate host immune response was hypothesised to be the vaginal microbiome. This study investigated the effect of the vaginal environment (microbiome composition and metabolites) on the innate host immune response in pregnant women. Methods: Cervico-vaginal samples were obtained at two gestations (13-15+6 & 16-23+6 weeks; n=355 women; White n=233, black n=76, other n=34) from a prospective longitudinal cohort of women with written consent (INSIGHT study, NRES London City and East approval 13/LO/0393). Metabolites: measured using Bruker Avance II 700 NMR, with preprocessing/OPLS-DA using MVAPACK. Vaginal microbiome: determined by sequencing the V1-V2 region of the 16S rRNA gene and data analysed using the mothur pipeline. Operational taxonomic units were constructed at 98.5% similarity and classified by comparison to the vaginal microbiome database. Sample composition between groups was compared by AMOVA applied to a theta-YC dissimilarity matrix. Elafin and cathelicidin measured by ELISA. Results: Early pregnancy microbiome composition was significantly influenced by maternal ethnicity (AMOVA, p<0.001) with differences in microbiome, metabolome, host immune responses relationships and sPTB identified for Black and White women. A correlation between microbiome and sPTB (AMOVA, p=0.036 and p=0.004 for early and later pregnancy) was only observed in White women, in parallel with increases in acetate and cathelicidin. Conclusion: Specific bacterial species/community states or metabolites are unlikely to be a global indictor of risk in heterogenous antenatal populations. Research into mechanisms of preterm birth and biomarkers must consider confounders such as ethnicity. A ‘precision medicine' based approach to prediction of sPTB is required.

Where applicable, experiments conform with Society ethical requirements