Robert Hettich
Oak Ridge National Laboratory, USA
Title: Characterizing temporal and inter-individual functional differences in pre-term human infant gut microbiome development by a metaproteomics approach
Biography
Biography: Robert Hettich
Abstract
Details about microbial species population structure and functional dynamics during microbiome establishment are poorly
understood in the human infant gut. Th e objective of this work is to exploit a high performance LC-MS/MS based metaproteomic
approach to explore host and microbiome temporal functional shift s during microbial colonization of the pre-term infant gut. Fecal
metaproteomes of nine pre-term infants were measured at discrete time-points over several months. Approximately 10,000 human
and microbial protein groups were identifi ed in each infant. In early time points, human proteins were more abundant than microbial
proteins, and comprised pathways involving epithelial barrier establishment and immune response. Intriguingly, comparison of
genomic and proteomic patterns identifi ed some microbial species that were both active and in low abundance. Most functional
core metabolic processes were conserved in the microbiome; however, temporal and inter-individual variations were identifi ed. For
example, lipid metabolism (specifi cally glycerol degradation) was dominant early in one infant, and progressed to predominantly
amino acid metabolism over time, in stark contrast to other pre-term infants. Th ese diff erences are likely related to microbiome or
environmental factors that distinguished the infants. In response to bacterial colonization, the human hosts expressed proteins that
play pivotal roles in the integrity and barrier properties of mucosal epithelial layers. Th e time-course metaproteomics measurements
revealed core metabolic pathways in both human and microbial proteins, revealing the establishment of the mutualistic relationship
between the microbiome and human host early in infancy. In total, these results reveal functional stability and inter-individual
signatures of the preterm infant gut microbiome.