Final answer:
Without regular feeding, the GI tract may experience decreased motility and increased gut permeability. Enteral nutrition is generally preferred over parenteral nutrition due to its benefits in maintaining gut integrity and reducing complications.
Step-by-step explanation:
The question explores the changes of the gastrointestinal (GI) tract in the absence of feeding and the mortality advantage of enteral nutrition (EN) versus parenteral nutrition (PN). When the GI tract is not being used for feeding, several changes occur:
- Decreased gastric motility: The autonomic nervous system controls the GI tract. Sympathetic activation can decrease GI secretion and motility, which occurs without regular feeding.
- Increased gut permeability: Lack of nutrients and decreased blood flow can lead to changes in the mucosal barrier, increasing permeability.
- Improved nutrient absorption does not typically occur without feeding; instead, it requires a functioning digestive system with food present.
- Enhanced gastric acid secretion is typically stimulated by the presence of food; without feeding, the secretion may diminish.
EN has a mortality advantage over PN as it maintains gut integrity, stimulates the immune system, and is associated with fewer complications like infections and metabolic imbalances.