Factors affecting infant gut microbiota development, with Prof. Christopher Stewart PhD

This episode features Prof. Christopher Stewart PhD from Newcastle University (UK), speaking about the factors affecting gut microbiota development in both non-preterm and preterm infants. Prof. Stewart started in the field of environmental microbial ecology and then came to work in human microbiome research. He was involved in the landmark TEDDY study, which aimed to find gut microbial markers of type 1 diabetes (T1D). Although no microbial triggers of T1D were identified, the study found a number of factors that impact gut microbiome development: for example, sex, geographical location, and living with furry animals. Still, most of the variation seen in the infant gut microbiota remains unaccounted for. He noted that infants are exposed to both vaginal and gastrointestinal microorganisms during vaginal birth. In C-section-born infants, seeding of the maternal vaginal and gut microbiota may be promising, but current methods are imprecise and safety has not been established. Furthermore, diet takes over as a primary driver of gut microbiota a few weeks after birth. Prof. Stewart talked about human milk oligosaccharides (HMOs), well known to be utilized by bifidobacteria in the infant gut. His lab recently published the surprising finding that Clostridium species can also utilize HMOs – and while at first this was thought to be detrimental for the infant, further investigation showed that the HMO-utilizing Clostridium may lack the genes for producing specific toxins and end up being protective for the infant gut. Together, the microbial community in the gut may use the full suite of HMO substrates reaching the infant gut. Preterm infants are a population that needs more attention. Antibiotics affect their gut microbiomes – often in a negative way, but for the overall benefit of the baby. His lab is currently funded to study how probiotics affect the preterm infant gut microbiota, and to find strategies for more personalized approaches to administering probiotics in this population. Episode abbreviations and links: TEDDY study, revealing factors affecting gut microbiota development between 3 and 46 months of age: Temporal development of the gut microbiome in early childhood from the TEDDY study Study on how Clostridium species utilize HMOs: Clostridia from preterm infants metabolize human milk oligosaccharides to suppress pathobionts and modulate intestinal function in organoids Study on how NEC risk is linked with HMOs: Human milk oligosaccharide DSLNT and gut microbiome in preterm infants predicts necrotising enterocolitis  Publication on how probiotics impact the gut microbiota in preterm infants: Strain-specific impacts of probiotics are a significant driver of gut microbiome development in very preterm infants Some similar results have come from the CHILD Cohort Study, described here Find Prof. Stewart on LinkedIn, and learn more about his research on this website About Prof. Christopher Stewart: Professor Christopher Stewart is an internationally recognised leader in human microbiome research. He earned his PhD in Microbial Ecology from Northumbria University (UK), followed by postdoctoral training at Baylor College of Medicine (Houston, Texas), before establishing his research group at Newcastle University in 2018. His pioneering work focuses on microbial-host interactions in the gut, particularly in infants born extremely premature (<32 weeks gestation). His lab integrates multi-omic analyses of clinical samples with experimental microbiology and organoid co-culture systems to uncover mechanisms of microbial influence on early-life development. More recently, he has expanded his research to support a UK-wide initiative investigating microbiome-based predictors of therapeutic response in adult inflammatory bowel disease. Professor Stewart has published over 140 peer-reviewed articles in leading journals, contributing to the discovery of novel biomarkers and targeted microbiome-based interventions. He has received numerous prestigious awards, including the Blavatnik Award for Life Sciences Laureate, the Lister Institute Research Prize, the Microbiology Society Fleming Prize, the NOSTER & Science Microbiome Finalist Prize, the Applied Microbiology International WH Pierce Prize, and the Neonatal Society Rising Star Award.  His research has broad implications for understanding diet–microbe–host interactions and improving health across the life course, miology, maternal and child health, and microbiome science, with a particular emphasis on the effects of vaginal microbiota transfer (VMT) on the microbiota composition and health outcomes of cesarean-delivered infants.