# Perinatal Precursors of Early Microbiome Development.

> **NIH NIH R01** · UNIVERSITY OF CALIFORNIA, SAN FRANCISCO · 2021 · $627,207

## Abstract

Project Summary
There is growing evidence that fetal exposure to glucocorticoids may contribute to a variety of adverse birth
outcomes. Recent concern has emerged regarding the fetal effects of antenatal corticosteroids (AC)
administered as preventive care to women who are at risk of preterm birth. Although they effectively reduce the
likelihood of certain neonatal morbidities, our previous research found that neonates whose mothers were
prescribed corticosteroids had significantly depleted and unusual gut microbiota in the first month of life, in
contrast to neonates whose mothers did not receive them. We also found that a mother's symptoms of
depression predicted a significant amount of variance in infant gut microbiota composition, with both more
severe depression and higher levels of stress associated with a greater abundance of bacterial species that
modulate metabolism of steroids. Importantly, sex differences also emerged. The bacterial taxa of male infants
were significantly depleted in contrast to girls; and their microbial compositions differed. Lastly, our research
indicates that bacterial structure of the maternal vaginal microbiome (a key source of microbes for the neonatal
microbiome) is affected by maternal stress. Transmission of altered bacterial communities during vaginal
delivery may disrupt neonatal microbial environments that are essential for health. To validate and extend our
preliminary findings, we propose to determine: 1) if AC or maternal emotional distress in pregnancy are
associated with a distinct neonatal gut microbiome that differs from neonates whose mothers did not receive
AC or were not distressed, and 2) if distinct microbial genes and gene pathways identified at birth are
sustained or increased through early life. Our primary focus will be on microbial species that metabolize
glucocorticoids. We will also determine if AC and emotional distress are associated with a distinct maternal
vaginal microbiome and whether these vaginal microbes are found in the neonatal gut microbiome. Finally, we
will examine the moderating effect of fetal/infant sex in all analyses. 160 women will complete measures of
depressive symptoms and stress, provide a vaginal specimen, and covariate measures in pregnancy. Stool
samples will be acquired from infants at birth and at 1 month and 3 months postnatal, along with further
measures of maternal stress, depressive symptoms and covariates. The medical record will provide data on
AC as well as additional covariates that will be controlled for in analyses. Multilevel regression modeling will be
used to examine the aims, along with elastic, net and weighted network analyses, in addition to integrated
analyses of metagenomics and metabolomics for maternal vaginal and neonatal gut datasets. Exposure to AC
and maternal emotional distress during pregnancy could have implications for early programming of the infant's
microbiome and future disruption of adaptive function that is critical to the c...

## Key facts

- **NIH application ID:** 10251243
- **Project number:** 5R01HD102604-02
- **Recipient organization:** UNIVERSITY OF CALIFORNIA, SAN FRANCISCO
- **Principal Investigator:** Susan Veronica Lynch
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2021
- **Award amount:** $627,207
- **Award type:** 5
- **Project period:** 2020-09-01 → 2024-07-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10251243

## Citation

> US National Institutes of Health, RePORTER application 10251243, Perinatal Precursors of Early Microbiome Development. (5R01HD102604-02). Retrieved via AI Analytics 2026-05-24 from https://api.ai-analytics.org/grant/nih/10251243. Licensed CC0.

---

*[NIH grants dataset](/datasets/nih-grants) · CC0 1.0*