Development of digestive and absorptive function in the human fetus

Area of Science:

• Neonatal physiology
• Gastrointestinal development

Background:

• Digestive enzyme activity and intestinal absorptive functions are critical for infant nutrition.
• Understanding these functions in newborns, especially premature infants, is essential for assessing nutritional status.

Purpose of the Study:

• To characterize the developmental status of digestive enzymes and intestinal absorptive functions in human newborn infants.
• To identify specific patterns in enzyme activity and absorption, particularly concerning fat absorption in premature infants.

Main Methods:

• Analysis of pancreatic alpha-amylase activity in mature newborn infants.
• Assessment of the developmental trajectory of other digestive enzymes with age.
• Evaluation of intestinal absorptive functions during pregnancy and in newborns.
• Monitoring of fat absorption in premature infants during the first month of life.

Main Results:

• Mature newborn infants exhibit very low but inducible pancreatic alpha-amylase activity.
• Other digestive enzymes show rapid age-related increases, nearing adult levels.
• Intestinal absorptive functions are largely developed by mid-pregnancy and are at adult levels in newborns.
• Premature infants demonstrate initially low fat absorption, which rapidly improves within the first postnatal month.

Conclusions:

• Neonatal digestive enzyme activity is characterized by low basal levels with significant inducibility, particularly for pancreatic alpha-amylase.
• Intestinal absorptive capacity is well-established at birth, ensuring efficient nutrient uptake in mature newborns.
• Premature infants require specific attention regarding fat absorption, as this function matures postnatally.