Project Director: Mark McGuire

Project Team: Janet Williams, Sarah Brooker, Chris Remien, Ben Ridenhour, JT Van Leuven

Myriad microbial communities within and on the human body interact constantly with each other and environmental factors, and although much work has focused on characterizing these various community structures (especially in adults), almost nothing is known about how those of mothers and infants interact. Understanding this crosstalk is likely critical to understanding the establishment of the gastrointestinal (GI) microbiome in early life and how it influences risk for diseases and conditions such as necrotizing enterocolitis, diarrhea, obesity, and Crohn’s disease. However, development of GI microbial community in infancy has been relatively poorly studied. Nonetheless, its complexity is known to be substantial and tracking individual species may not provide the knowledge to impact human health.

Here, we propose to model the development of breastfed infants’ GI tract in connection with various sites within the mother-infant dyad and examine potential effect modifiers, such as maternal/infant nutrition, mode/location of delivery, and antibiotic use. For instance, studies have demonstrated that the bacterial community in milk may influence the development of infant’s GI tract. Other studies have shown that maternal consumption of targeted probiotics can alter the bacteria in the milk she produces. Thus, it is possible that the bacterial community in a woman’s GI tract can also alter that of her infant. Other sites of within a woman, such as the skin and saliva, may contribute to milk and infant fecal microbiomes as well. For these reasons, we have collected samples from mothers (milk, breast skin, feces and saliva) and infants (feces and saliva) from birth through 6 mo postpartum to examine these and other relationships. In this project, we will leverage this complex dataset (which includes both quantitative and qualitative empirical data) to model never-before-evaluated relationships among environmental/behavioral factors and multiple microbial communities in mothers and their infants over time. Because of the intimate and emerging connections between microbial communities and health, we anticipate that these findings will lay a solid foundation supporting additional collaborative studies related to the manipulation of early-life microbial communities for optimal acute and chronic health.