Influence of Physical Treatments of Human Milk on the Kinetics of Gastric Lipolysis in Preterm Newborns (ARCHILACT)

Influence of Physical Treatments of Human Milk on the Kinetics of Gastric Lipolysis in Preterm Newborns

Influence of Physical Treatments of Human Milk on the Kinetics of Gastric Lipolysis in Preterm Newborns

The optimization of newborns nutrition is a challenge especially for preterm newborns for whom nutrition plays a crucial part in cerebral and global development. Human milk is considered as the best food for newborns. Several short and long-term beneficial health effects were attributed to breastfeeding and have induced the increase of human milk in preterm newborns nutrition. Whereas the chemical composition of infant formula has been optimized to mimic human milk, there is still a major difference between the structure of human milk and commercial infant formulas. It is well known in adult nutrition that the structure of emulsions influences their susceptibility to hydrolysis, such results have been obtained either on in vitro or in vivo studies. Human milk is a natural emulsion (oil in water). Lipids droplets are dispersed under the form of entities called milk fat globules (average diameter 4 µm, span 0.1-20 μm). The globules are stabilized by a trilayered membrane composed mainly of polar lipids (phospholipids, sphingolipids and gangliosides), of proteins, neutral lipids and other minor compounds. The physical treatments apply to human milk or more generally to bovine milk to pasteurize or stabilize the milk modify the structure of the natural emulsion. Heat treatment for instance induces whey proteins denaturation and the adsorption of protein aggregates on the surface of the milk fat globules. Heat treatment also leads to the denaturation of bile salt stimulated lipase. These effects limit intragastric lipolysis in preterm newborns. Conversely, reduction of milk globules size, by homogenisation of milk, increases the specific surface available for lipase adsorption and limits the lost of fat during enteral administration of milk. Such treatment could thus enhance gastric lipolysis and improve fat absorption of preterm newborns. The objective of this trial is to evaluate the effects of physical treatments (pasteurization and homogenisation by ultrasonication) applied to human milk on gastric lipolysis and milk destructuration. This trial is conducted, in vivo, on preterm newborns.

Raw human milk compared to pasteurized human milk. Two meals administration (20mL/kg) per day during 6 days in a randomized order, with an intragastric tube : one with raw milk and one with pasteurized milk. In order to characterise gastric effluents at different postprandial times after ingestion and to measure gastric lipolysis and proteolysis, at each administration two gastric samples will be collected with the intragastric tube : one before the meal, and one either 35, 60 or 90 minutes (randomized time frame) after the meal.

Pasteurized human milk compared to pasteurized-homogenized human milk. Two meals administration (20mL/kg) per day during 6 days in a randomized order, with an intragastric tube : one with pasteurized milk and one with pasteurized-homogenized milk. In order to characterise gastric effluents at different postprandial times after ingestion and to measure gastric lipolysis and proteolysis, at each administration two gastric samples will be collected with the intragastric tube : one before the meal, and one either 35, 60 or 90 minutes (randomized time frame) after the meal.

Fat composition by chromatographic techniques : High-Performance Liquid Chromatography (HPLC), Gas Chromatography (GC)

Inclusion Criteria: Premature neonates born before 32 weeks of gestation Newborn dwelled near Rennes Volume of enteral nutrition > 120 mL/kg/j (Day 0) Written-informed parental consent for the study Exclusion Criteria: Digestive congenital anomalies Antecedent of enterocolitis Patient included in other study Abdominal distension on Day 0 Treatment by morphine or catecholamine on Day 0

Agrocampus Ouest - Département AgroAlimentaire UMR 1253 INRA " Science et Technologie du Lait et de l'Oeuf ", Rennes, FRANCE

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de Oliveira SC, Bellanger A, Menard O, Pladys P, Le Gouar Y, Henry G, Dirson E, Rousseau F, Carriere F, Dupont D, Bourlieu C, Deglaire A. Impact of homogenization of pasteurized human milk on gastric digestion in the preterm infant: A randomized controlled trial. Clin Nutr ESPEN. 2017 Aug;20:1-11. doi: 10.1016/j.clnesp.2017.05.001. Epub 2017 May 15.

de Oliveira SC, Bellanger A, Menard O, Pladys P, Le Gouar Y, Dirson E, Kroell F, Dupont D, Deglaire A, Bourlieu C. Impact of human milk pasteurization on gastric digestion in preterm infants: a randomized controlled trial. Am J Clin Nutr. 2017 Feb;105(2):379-390. doi: 10.3945/ajcn.116.142539. Epub 2017 Jan 4.