对照组采用常规治疗：入选早产儿均同时接受各系统支持等基础治疗，在患儿达

Control group with conventional therapy: preterm children were enrolled while receiving basic treatment systems support each other in giving children reach a unified front full enteral feeding PN management. For children deposition occurs in addition to conventional use of liver bile treatment, are used ursodeoxycholic acid (Germany Hawke pharmaceutical production, 250mg / grain, 10-15mg / kg.d, orally, sub-2) combined jaundice Inn Chen particles (Shanghai Jing pharmaceutical production, 20g / bag, 3g / times, orally, three times a day) The course of treatment an average of 10 days. Bifidobacterium group on the basis of conventional therapy plus service bifidobacteria (Bifidobacterium be scattered oral triple viable within 24 hours after birth, 0.5g / time, 3 times / d), until the full enteral feeding times.

The control group used conventional therapy: the selected premature babies received basic treatment such as system support at the same time, and given unified PN management before the child reached full gastrointestinal feeding. For children with bile siltation in addition to the conventional use of liver protection treatment, are using bear deoxycholic acid (German Hawke PharmaceuticalS production, 250 mg / grain, 10-15mg/kg.d, oral, divided into 2 times) joint jaundice chen particles (Shanghai Jing'an Pharmaceutical Factory production, 20g / pack, 3g / times, oral, 3 times a day) treatment, the average course of treatment 10 days. Bifidobacteria group on the basis of conventional treatment to add Bifidobacteria (within 24 hours after birth to Doubledobacteria trifidobacteria dispersed oral, 0.5g/time, 3 times/d) until the whole gastrointestinal feeding time.

Routine treatment was used in the control group: all preterm infants received basic treatment such as support from all systems at the same time, and they were given unified PN management before they reached the whole gastrointestinal feeding. In addition to the routine treatment of liver protection, ursodeoxycholic acid (250mg / pill, 10-15mg / kg. D, oral, twice) and jaundice Yinchen granules (20g / bag, 3G / time, oral, three times a day) were used in the treatment of cholestasis. The average course of treatment was 10 days. On the basis of routine treatment, the bifidobacteria group was given bifidobacteria (0.5g/time, 3 times / day, oral bifidobacteria triple viable powder within 24 hours after birth) until the whole gastrointestinal feeding time.