The Effects Of Extensively Protein Hydrolysed Formula On The Gastrointestinal Function In Preterm Infants And Probable Mechanisms

Objective:To evaluate the effects of extensively protein hydrolysed formula on the gastrointestinal function in preterm infants and explore the probable mechanisms.Methods:Preterm infants(gestational age≤34 weeks and birth weight≤2000g) who were hospitalized into neonatal intensive care unit in Union hospital of Tongji Medical College, Huazhong University of Science and Technology within their first 24 hours, were randomly assigned into the group I(extensively protein hydrolysed formula) or group II(standard preterm formula). During the period of hospitalization the subjects'enteral feeding situations were recorded daily, and the weight were measured every other day early in the morning. Fasting bloods were collected for testing of blood biochemical indices in biochemistry laboratory and serum motilin(MOT), gastrin(GAS), amylin(AMY) by enzyme-linked immunosorbent assay(ELISA) on the first, seventh and fourteenth day respectively. Additionally, the levels of peripheral blood glucose and total bilirubin were monitored, and infections were also recorded.Results:There were 50 cases eligible for the study and 25 cases in each group.1.There were no statistically differences with regard to the indicators of gastrointestinal function(all P>0.05), but the time of feeding intolerance, indwelling nasogastric tube, enteral feeding achieving 100ml/(kg ? d), stools turning into yellow and parenteral nutrition all tended to be shorter.2.The highest serum total bilirubin (TBIL) levels of group I were lower than these of group II[(162.00±53.14)umol/L vs (208.33±78.08) umol/L](P<0.05), and the duration of serum TBIL returning to normal in group I were shorter compared with group II [(7.7±1.6)d vs (9.2±2.0)d](P<0.01). The serum total bile acid (TBA) levels on the fourteenth day of group I were lower than these of group II [(10.9±5.4)umol/L vs (26.7±19.2)umol/L] (P<0.05).3.Motilin(MOT), gastrin(GAS) and amylin(AMY): Both the levels of MOT and GAS in two groups showed an upward trend, and the group I tended to be higher than group II. The levels of AMY on the seventh day in both groups tended to be higher than these of the first day, then showed a decline on the fourteenth day. The levels of AMY on the seventh day in group I tended to be lower. These differences were all not statistically significant(P>0.05).4.There were no significant differences with regard to the time of recovering into birth weight, the levels of serum albumin(A), prealbumin(PA), blood urea nitrogen(BUN), calcium, phosphorus, and alkaline phosphatase(ALP) on the first, seventh and fourteenth day in two groups(P>0.05), but the levels of ALP on the fourteenth day in group I tended to be higher.Conclusion:1.The protein hydrolysed formula may be beneficial to bilirubin metabolism and may can reduce cholestasis in preterm infants.2.The hydrolysed protein formula shows a beneficial tendency on improving early gastrointestinal function in preterm infants compared with standard preterm formula.3.The long-term effects of this formula on the growth and development in preterm infants still need longer follow-up.