Impact of homogenization of pasteurized human milk on gastric digestion in the preterm infant: A randomized controlled trial

Abstract

It has been suggested that homogenization of Holder-pasteurized human milk (PHM) could improve fat absorption and weight gain in preterm infants, but the impact on the PHM digestive kinetics has never been studied. Our objective was to determine the impact of PHM homogenization on gastric digestion in preterm infants. In a randomized controlled trial, eight hospitalized tube-fed preterm infants were their own control to compare the gastric digestion of PHM and of homogenized PHM (PHHM). PHM was obtained from donors and, for half of it, was homogenized by ultrasonication. Over a six-day sequence, gastric aspirates were collected twice a day, before and 35, 60 or 90min after the start of PHM or PHHM ingestion. The impact of homogenization on PHM digestive kinetics and disintegration was tested using a general linear mixed model. Results were expressed as means±SD. Homogenization leaded to a six-fold increase in the specific surface (P<0.01) of lipid droplets. The types of aggregates formed during digestion were different between PHM and PHHM, but the lipid fraction kept its initial structure all over the gastric digestion (native globules in PHM vs. blend of droplets in PHHM). Homogenization increased the gastric lipolysis level (P<0.01), particularly at 35 and 60min (22 and 24% higher for PHHM, respectively). Homogenization enhanced the proteolysis of serum albumin (P<0.05) and reduced the meal emptying rate (P<0.001, half-time estimated at 30min for PHM and 38min for PHHM). The postprandial gastric pH was not affected (4.7±0.9at 90min). Homogenization of PHM increased the gastric lipolysis level. This could be a potential strategy to improve fat absorption, and thus growth and development in infants fed with PHM; however, its gastrointestinal tolerance needs to be investigated further. This trial was registered at clinicaltrials.gov as NCT02112331.