# Impact of Maternal Antibiotics on the Breastfeeding Infant Microbiome and Metabolome

> **NIH NIH P50** · UNIVERSITY OF CALIFORNIA, SAN DIEGO · 2024 · $338,824

## Abstract

PROJECT SUMMARY
This data science project proposal seeks to utilize innovative methods in untargeted
metabolomics and microbiome analysis to study the effect of maternal antibiotic exposure in
breastfeeding infants. When breastfeeding mothers are taking antibiotics for common infections,
the infant's microbiome and their metabolism may be affected. This could have long-term
consequences on the infant's overall health because of the important role of the microbiome in
health and disease. It can be difficult to monitor drug effects in infants because of their low
blood volume and the invasiveness of blood draws. We have been able to non-invasively
monitor drugs in skin using skin swabs. We think this may be an important new way to monitor
drugs in infants. The three areas to be investigated in this project are:
Aim 1: Monitor infant antibiotic exposure levels through breast milk by monitoring the
skin metabolome using non-invasive swabs. We will test skin from breast milk fed infants
whose mothers were given antibiotics, breast milk fed infants whose mothers were not given
antibiotics, and infants who are not breast fed whose mothers were given antibiotics from
Project 1. Untargeted metabolomics and molecular networking will be used to detect antibiotics
and their metabolites in skin.
Aim 2: Determine the impact of antibiotic exposure through breast milk on the infant
microbiome, metabolome and metabolic transformation capacity.
Infant fecal samples obtained from Project 1 will be analyzed for changes in the microbiome due
to antibiotics from the mother. We will compare how the four different antibiotics given in the
clinical study affect the infant microbiome and metabolome.
Aim 3: Elucidate the gut metabolic transformations in infant mice from direct or indirect
(via maternal treatment or breastfeeding) exposure to ampicillin and investigate if host
cytochrome P450 (CYP) activities are altered. Mouse samples obtained from Project 2 will
be analyzed using new data science applications to determine the effect of ampicillin through
breast milk on the infant's metabolism throughout the intestine and the liver including the
cytochrome P450 drug metabolizing enzymes (Cyp). We will also have the targeted analysis of
ampicillin in breast milk from our Pharmacometrics and Analytical Chemistry Core and the
breast milk analysis from the Milk Analytics Core to complement our untargeted approaches.
We will also assess the effect of ampicillin on Cyp activity in the mouse intestine and liver.

## Key facts

- **NIH application ID:** 10907657
- **Project number:** 5P50HD106463-04
- **Recipient organization:** UNIVERSITY OF CALIFORNIA, SAN DIEGO
- **Principal Investigator:** Shirley M Tsunoda
- **Activity code:** P50 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2024
- **Award amount:** $338,824
- **Award type:** 5
- **Project period:** 2021-09-10 → 2026-07-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10907657

## Citation

> US National Institutes of Health, RePORTER application 10907657, Impact of Maternal Antibiotics on the Breastfeeding Infant Microbiome and Metabolome (5P50HD106463-04). Retrieved via AI Analytics 2026-05-24 from https://api.ai-analytics.org/grant/nih/10907657. Licensed CC0.

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