Skip to main content
SMFM 2024 Pregnancy Meeting Main banner
Final Program


Icon Legend
This session is not in your schedule.
This session is in your schedule. Click again to remove it.
Presentation Icons
Additional registration fee required
Additional registration fee required
Faculty have requested this content not be shared on social media
Faculty have requested this content not be shared on social media
CME Credit Offered
CME Credit Offered
Poster Icons
Foundation Awardee
Foundation Awardee
No Social Media
No Social Media
Back
Q&A

Basic Science

Poster Session 3

(816) Gut microbiome impacts iron deficiency and responsiveness to iron supplementation in a prospective, interventional trial

Wednesday, February 14, 2024
8:30 AM – 10:00 AM  
Location: Prince George's Exhibit Hall CDE, Lower Atrium Level
Objective: Oral iron absorption in the gut is regulated to optimize bioavailability & overcome iron losses. However, response to iron supplementation (IS) is unpredictable. We hypothesized that variation in the composition of the gut microbiome would vary between responders vs non-responders following IS.

Study Design: People who menstruate without a known history of anemia or iron deficiency were included in our open label, prospective, interventional trial (n=26). Participants received 14 days of 65mg elemental iron. Blood (Days (D) 0 & 14) & stool (8 samples including D0 & D14) were collected for iron & anemia indices and microbiome analyses. Stool sample DNA underwent 16S amplicon sequencing and bioinformatic analysis of microbial ASVs (DADA2). To characterize the gut microbiome composition, taxonomic comparisons, & unsupervised clustering with Dirichlet multinomial mixtures (DMM) were performed. Participants who were iron deficient on D0 (n=17) were later subdivided into iron supplement responders (ferritin ≥ 30 ng/mL, n=4) and non-responders (ferritin < 30 ng/mL, n=12), based on their D14 ferritin.

Results: Three taxa were associated with D0 iron deficiency (ferritin < 30 ug/L): Bacteroides, Streptococcus and Tyzzerella (p=0.021, 9.3e-05, 0.0024; Fig1A). Unlike Streptococcus and Tyzzerella, Bacteroides was inversely associated with baseline ferritin levels. In the D0 iron deficient group, IS response was associated with six keystone taxa: Ruminococcus, Bacteroides, Gordonibacter, Lachnoclostridium, Lactobacillus, and Lactococcus (p=0.013, 0.006, 0.008, 0.003, 0.004, 0.005; Fig1B). Increases in Ruminococcus, Gordanibacter, and Lactobacillus were associated with responders. Bacteroides remained more abundant in non-responders throughout the IS period.

Conclusion: Significant gut microbiome taxonomic differences were observed when comparing iron deficient and sufficient participants, and between IS therapy responders and non-responders. Thus, there is evidence for an impact of gut microbiome composition on iron deficiency and responsiveness to IS.