806 Diet quality is associated with vaginal alpha diversity in the first trimester of pregnancy

Abstract

Understanding environmental influences on the vaginal microbiome may help to translate to improved pregnancy outcomes. While some dietary patterns have been associated with improved vaginal microbial health, few studies have investigated the impact of comprehensive diet quality on this outcome. Our study aimed to associate Diet Quality as defined by the Healthy Eating Index (HEI) with alpha diversity metrics longitudinally across pregnancy in healthy, low risk pregnancy women. Forty women were recruited, 10 from the 4 largest ethnic groups in Hawaii. Diet Quality indices were assigned from Food Frequency Questionnaires (FFQs) during each trimester (12 weeks, 20 weeks and 34-36 weeks). Vaginal swabs were collected from the mid-vagina concomitantly at each time point, from which DNA extraction and 16s rRNA sequencing were performed. Alpha and beta diversity profiles were assigned, and correlated in a linear fashion with HEI Score. Linear regression models were also used to account for confounding demographic factors. Longitudinal data was available for 35 participants. HEI score was stable across pregnancy, and correlated with alpha diversity metrics during the first trimester. Diet quality did not impact richness or evenness during the second or third trimester. There were no detectable differences between ethnicities, weight class, or pregnancy outcomes. 4 Community State Types predominated: Lactobacillus iners, Lactobacillus crispatus, Lactobacillus gasseri, and lactobacillus deficient/mixed anaerobes predominant), and were evenly distributed among four quartiles of HEI scores. Overall a paucity of the Lactobacillus jensenii species was noted. Alpha diversity decreased throughout pregnancy in this cohort, commensurate with other studies. Diet quality was most associated with microbial composition in the first trimester, but likely has lesser impact on microbial transition than hormonal factors as pregnancy progresses.