Neonatal fat digestion and lingual lipase

Area of Science:

• Neonatal nutrition
• Gastroenterology
• Enzymology

Background:

• Infant digestion relies on enzymes like lingual lipase (LL) for fat hydrolysis.
• Preterm infants often receive formula via nasogastric tube, potentially affecting digestive processes.
• Understanding lingual lipase function is crucial for optimizing infant nutrition.

Purpose of the Study:

• To investigate lingual lipase activity, gastric pH, and fat hydrolysis products in preterm infants receiving formula feeds.
• To compare lingual lipase activity between tube feeding and bottle feeding methods.
• To explore the influence of feeding method on gastric digestion in preterm infants.

Main Methods:

• Gastric aspirates were collected from preterm infants fed formula via nasogastric tube at varying intervals (1, 2, 3-hourly).
• Lingual lipase activity, pH, triglyceride levels, and hydrolysis products (diglycerides, free fatty acids) were measured.
• A cross-over study compared lingual lipase activity after bottle versus tube feeding in 3-hourly fed infants.

Main Results:

• Lingual lipase activity peaked at specific times post-feed (60-120 min) depending on feeding frequency.
• Gastric pH decreased significantly from ~6.0 to <3.5 after feeds.
• Triglyceride content reduced by 50%, with diglycerides and free fatty acids as primary hydrolysis products.
• Lingual lipase activity was significantly higher following bottle feeds (23.8 µmol FFA/ml/h) compared to tube feeds (19.1 µmol FFA/ml/h).

Conclusions:

• Substantial triglyceride hydrolysis occurs in the stomach of preterm infants, primarily mediated by lingual lipase.
• Bottle feeding, potentially due to sucking, leads to enhanced lingual lipase production compared to tube feeding.
• These findings highlight the importance of feeding method in optimizing fat digestion and nutrient absorption in preterm infants.