(610) Maternal exposure to benzo[a]pyrene, a harmful PAH pollutant, is associated with altered microbial metabolite pathways

Thursday, February 9, 2023

4:00 PM – 5:30 PM

Objective: Fetal exposure to environmental toxins, such as polycyclic aromatic hydrocarbons (PAHs), is associated with the development of later-in-life disease, including asthma and obesity. However, the mechanisms for this increased risk remain largely unknown. We and others have shown that gut microbiota are major players in xenobiotic metabolism, and that the maternal microbiome strongly influences development of the infant microbiome. In this study we sought to determine if there are significant changes to the maternal and offspring gut microbiome with exposure to benzo[a]pyrene (BaP), a toxic and ubiquitous PAH.

Study Design: Female mice (C57BL7, n=7) were orally gavaged with BaP (30 mg/kg) within 12 hours of mating (Fig 1a). Oral administration of BaP (or corn oil control) was repeated on gestational days 11, 12, 16 & 19, and stool samples were collected daily. Total microbial DNA from stool and appropriate negative controls were 16S-amplicon sequenced (V4). Reads were QCed, processed into ASVs and classified using DADA2 in R. PICRUSt2 was utilized for inferred pathway analysis. Comparisons were subjected to ANOVA and Posthoc Tukey-Kramer (correcting for multiple comparisons).

Results:

Although (1) alpha diversity (Shannon Index; p=0.068) and (2) taxonomic community composition (beta diversity) of BaP exposed dams was not significantly different (Fig.1b), there was a significant decrease (p < 0.05) in predicted aromatic hydrocarbon biosynthesis pathways in the BaP treated dams (Fig. 1c).

Conclusion:

Environmental toxin exposure through ingestion can directly influence composition of the maternal gut microbiome and the inferred microbial metabolite pathways, resulting in changes in her offspring’s gut microbiome ecology. Further studies on alterations of the offspring microbiome following in utero exposure to PAHs may provide insight of environmental chemical and microbiome interactions during early developmental windows.

Primary & Presenting Author(s)

Sohini Banerjee, PhD (she/her/hers)
Baylor College of Medicine
Houston, Texas, United States

Coauthor(s)

Melissa Suter, PhD
Baylor College of Medicine
Houston, Texas, United States
JW
Jiang Weiwu, MS
Baylor College of Medicine
Houston, Texas, United States
BM
Bhagavatula Moorthy, PhD
Texas Children's and Baylor College of Medicine
Houston, Texas, United States
Kjersti M. Aagaard, MD,PhD
Professor and Vice Chair of Research Department of Obstetrics and Gynecology, Division of MFM
Texas Children's and Baylor College of Medicine
Houston, Texas, United States