George Liu | Peripartum Antibiotics, Microbiota & Neonatal Immunity | MPRINT 2026 | Day 4

Peripartum Antibiotic Exposure Disrupts Maternal-Infant Microbiota and Metabolome, and Impairs Neonatal Vaccine Immunity Presented by George Liu, MD, PhD Chief and Professor Pediatric Infectious Diseases University of California San Diego Recorded 4/16/2026 at the 2026 MPRINT Annual Meeting. In this presentation, Dr. George Liu discusses how peripartum antibiotic exposure may alter maternal and infant microbial communities, disrupt metabolic pathways, and affect the development of neonatal immune responses. While antibiotics are commonly administered during pregnancy, labor, and the neonatal period to prevent and treat infections, growing evidence suggests that these interventions may have unintended consequences for early-life immune development. Dr. Liu reviews the importance of the maternal and infant microbiome in shaping neonatal immunity and vaccine responsiveness. He describes how microbial colonization during the perinatal period influences immune maturation, host metabolism, and the development of protective responses to infectious diseases. Using data from both animal models and human studies, Dr. Liu presents evidence that peripartum antibiotic exposure results in significant alterations in microbial diversity and metabolomic profiles. These changes affect key bacterial taxa and microbial metabolites that play important roles in immune system development. The presentation demonstrates how antibiotic-associated disruptions may impair immune responses to routine childhood vaccines and alter the trajectory of immune maturation. Dr. Liu also discusses emerging strategies to mitigate these effects, including microbiome restoration approaches and targeted interventions aimed at preserving beneficial microbial functions during early life. The work highlights the importance of balancing the benefits of antibiotic therapy with potential long-term consequences for maternal and infant health. About MPRINT: The Indiana CTSI Pharmacometric Modeling and Simulation Program and Maternal Pediatric Precision in Therapeutics Hub (MPRINT Hub) supports collaboration, education, and research in pharmacometrics, model-informed drug development, translational science, and clinical pharmacology. Conference details: Event: MPRINT Annual Meeting 2026 Day: 4 Date: April 16, 2026 Location: Hine Hall, Indianapolis, IN Chapters: 00:00 Introduction 00:19 Background and clinical motivation 01:03 The infant microbiome and immune development 02:11 Antibiotic exposure during pregnancy and delivery 03:17 Maternal-infant microbial transmission 04:41 Animal model study design 06:03 Effects on microbial diversity 07:35 Metabolomic alterations following antibiotics 09:12 Immune development and vaccine responses 10:48 Mechanisms linking microbiota and immunity 12:37 Human cohort observations 14:18 Potential microbiome restoration strategies 15:42 Clinical implications 16:38 Future directions 17:15 Conclusions and acknowledgments Accessibility: Captions/subtitles are available for this video. Disclaimer: The views and opinions expressed in this presentation are those of the speaker and do not necessarily reflect those of the University of California San Diego, Indiana University, Purdue University, the Indiana CTSI, or affiliated organizations.