Fig. 1.

Metabolomic composition of small bowel effluent. A: weighted principal coordinate analysis of metabolite composition of small bowel samples from total parenteral nutrition (TPN), enterally fed (Fed), and germ-free (GF) mice. B: first principal component (PC; x-axis) and second principal component (y-axis) account for 90.1 and 5.4% of overall differences, respectively. C: list of identifiable compounds making up PC1 as determined by untargeted metabolomic analysis via LC/MS. D: crystalline amino acid (AA) composition of the TPN formulation administered to TPN-dependent mice. Circled AAs are those that comprise PC1 of analyzed enteral contents. VE, variance explained; USP, United States Pharmacopeia.