Metaproteomics of Premature Infant Gut Colonization

Microbial colonization of the human gastrointestinal tract plays an important role in establishing health and homeostasis. However, the time-dependent and related functional signatures of microbial and human proteins during early colonization of the gut have yet to be determined. Thus, we employed shotgun proteomics via nano-2D-LC-MS/MS to simultaneously monitor microbial and human proteins in fecal samples from a healthy preterm infant during early development. ). All MS/MS spectra were searched against a predicted protein database containing 25 microbial species along with the Human RefSeq2011 genome using the SEQUEST algorithm (Eng et al, 1994), and filtered with DTASelect version 1.9 (Tabb et al, 2002) at the peptide level with standard filters [SEQUEST Xcorrs of at least 1.8 (+1), 2.5 (+2) 3.5 (+3)] organizing identified peptides to their corresponding protein sequences. This study provides the first elucidation of coordinated human and microbial proteins in the infant gut during early development.