Bacterial colonization affects the intestinal proteome of preterm pigs susceptible to necrotizing enterocolitis.

Background: In newborns, colonizing bacteria and enteral nutrition are important for early gut development and immunity. However, in preterm newborns, bacterial colonization, coupled with enteral feeding, can lead to marked intestinal inflammation and disease such as necrotizing enterocolitis (NEC). We hypothesized that the initial bacterial colonization of the gut affects the intestinal proteome independently of enteral feeding.

Objective: To identify the intestinal proteins affected by the first colonizing bacteria by comparing the intestinal proteome in formula-fed preterm pigs reared under germ free (GF) or conventional conditions.

Methods: Gel-based proteomics of the small intestine to detect proteins that may play a part in the response of the immature intestine to bacterial colonization after birth.

Results: Fourteen proteins involved in stress response and detoxification (e.g. heat-shock proteins, peroxiredoxin 1), tissue metabolism and apoptosis (e.g. annexin 2), and some signal transduction pathways were differentially expressed between GF and conventionally reared pigs.

Conclusion: The premature intestine is highly responsive to initial bacterial colonization and the specific bacteria-related proteome changes may contribute to the stress response that makes the immature intestine sensitive to the pro-inflammatory effects of enteral feeding.