Intestinal transport during fasting and malnutrition
1Department of Pharmacology and Physiology, UMD-New Jersey Medical School, Newark, New Jersey 07103-2714, USA. ferraris@umdnj.edu
Annual Review of Nutrition
|August 15, 2000
Summary
Fasting and malnutrition significantly alter the small intestine, increasing fluid secretion and permeability while enhancing nutrient absorption per mucosal mass. Enteral nutrition is crucial for maintaining gut health during illness.
Area of Science:
- Gastroenterology and Nutritional Science
- Intestinal Physiology and Transport
Background:
- Fasting or malnutrition (FM) profoundly impacts small intestinal structure and function.
- Understanding these changes is critical for managing gastrointestinal health in various clinical settings.
Purpose of the Study:
- To elucidate the effects of fasting or malnutrition on small intestinal mucosal structure and transport.
- To investigate the mechanisms underlying altered ion, fluid, and nutrient transport in the small intestine during FM.
Main Methods:
- Analysis of small intestinal mucosal structure and function under conditions of fasting or malnutrition.
- Assessment of ion and fluid secretion.
- Evaluation of intestinal permeability to ions and macromolecules.
- Examination of nutrient absorption mechanisms, including transporter gene expression and cellular composition.
Main Results:
- FM increases basal and agonist-stimulated intestinal secretion of ions and fluid.
- FM elevates intestinal permeability to ions and macromolecules, potentially increasing fluid/electrolyte loss and allergic responses.
- Despite mucosal atrophy, nutrient absorption per unit of mucosal mass is enhanced via increased transporter expression and favorable electrochemical gradients.
Conclusions:
- Fasting or malnutrition induces significant adaptive changes in the small intestine.
- These adaptations include increased secretion and permeability, alongside enhanced nutrient absorption efficiency relative to mucosal mass.
- Enteral feeding is vital for preserving intestinal integrity and function in both health and disease states.
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