Diversity Intestinal Microbiota Associated With Necrotizing Enterocolitis

PART 1: STUDY ON THE CHANGE OF INTESTINAL MICROBIOTA OF PRETERM INFANTS WITH NECROTIZING ENTEROCOLITIS【Objective】 To investigate the change of intestinal flora structure of preterm infants with necrotizing enterocolitis by high-throughput sequencing.【Method】 In the period of June 2011 to June 2015,thirty-two hospitalized preterm infants in Shenzhen Children’s Hospital and Children’s Hospital of Chongqing Medical University were enrolled and divided into two groups: NEC group and control group with both 16 cases,the infants of the two groups were matched with each other by gestational age(±1 week),mode of delivery and day of life at NEC diagnosis(±3 days).According to gestational age,NEC group were divided into two subgroups,namely late preterm infants group(35W-36+6W)and moderate preterm infants group(30W-34+6W).Fecal samples of NEC patients were collected as soon as possible after the diagnosis was made,with an average collection time of 1 day after the diagnosis of NEC.After DNA extraction,the fecal samples of all enrolled infants were studied by high-throughput sequencing and then the results were analyzed by bioinformatics methods.【Result】 A total of 32 fecal samples were analyzed.The Shannon index of NEC group and control group was 0.77±0.60 and 0.97±0.34 respectively,The Simpson index was 0.67±0.22 and 0.53±0.15 respectively;Though there were no differences between NEC group and control group(P=0.09 、0.07,respectively).High-throughput pyrosequencing showed that the relative proportions of Corynebacterium strongly increased,whereas that of Lactobacillus was significantly reduced in NEC group compared with control group at genus level.At every subgroups,Corynebacterium were also significantly higher in the late preterm infants group with NEC and compared with the corresponding control group;Escherichia-Shigella were also significantly higher moderate preterm infants group with NEC compared with the corresponding control group.【Conclusion】Corynebacterium abundance increase and Lactobacillus abundance decrease associated with necrotizing enterocolitis.Change of intestinal microbiota may paly a role in the late preterm infants with NEC.Overgrowth of Escherichia-Shigella is closely connected with Moderate preterm infants with NEC.There are different composition of intestinal microbiota between late preterm infants with NEC and moderate preterm infants with NEC.PART 2: STUDY ON THE CHANGE OF INTESTINAL MUCOSA FLORA OF NEWBORNS WITH NECROTIZING ENTEROCOLITIS【Objective】 To investigate the change of intestinal mucosa flora structure of newborns with necrotizing enterocolitis by high-throughput sequencing.【Method】 In the period of June 2011 to Octomber 2015,fifteen hospitalized preterm infants in Shenzhen Children’s Hospital and Children’s Hospital of Chongqing Medical University were enrolled and divided into two groups: NEC group and control group are respectively 9 cases and 5 cases.After DNA extraction,the intestinal mucosa samples of all enrolled infants were studied by high-throughput sequencing and then the results were analyzed by bioinformatics methods.【Result】 A total of 15 fecal samples were analyzed.The Shannon index of NEC group and control group was 1.13±0.39 and 3.37±0.81 respectively,the Shannon index were significantly lower in NEC specimens compared to controls(P<0.001).The Simpson index of NEC group and control group was 0.47±0.19 and 0.12±0.04 respectively,the Simpson index were significantly higher in NEC specimens compared to controls(P<0.001).The Chao Richness of NEC group and control group was 110.8±72.17 and 456.4±84.33 respectively,The Ace Richness of NEC group and control group was 0.67±0.22 and 0.53±0.15 respectively;The Chao and Ace Richness were significantly lower in NEC specimens compared to controls(P<0.001).High-throughput pyrosequencing showed that the relative proportions of Corynebacterium and Acinetobacter strongly increased,whereas that of Bacteroides,Escherichia-Shigella,Erysipelatoclostridium and Campylobacterales was significantly reduced in NEC group compared with control group at genus level.【Conclusion】 Low bacterial diversity and richness in intestinal mucosa specimens may be indicative of the operatively NEC.Corynebacterium and Acinetobacter abundance increase and Bacteroides abundance decrease associated with necrotizing enterocolitis.There are different There are different composition of intestinal microbiota between fecal samples of NEC cases and intestinal mucosa samples of NEC cases.