Food allergy refers to the body's abnormal immune response to food,which induces disorder and/or injuries of human body,and thus triggers a series of manifestations.Ninety percent of food allergy is due to the following allergen:milk,eggs,peanuts,nuts,seafood,soy,wheat,etc.The symptoms of digestive system are closely associated with the nature of allergen (including protein's family nature,three dimensional structure,biological activity and stability) and the body's own status (genetic factors,integrity of intestinal mucosal barrier and oral immune tolerance).The symptoms of digestive systems are not typical,and differ by various factors like body conditions,ages,regions and allergens,so the diagnosis is difficult.Food allergy is categorized by its mechanism:IgE,non IgE,and mix.The symptoms of digestive systems include vomiting,diarrhea,reflux,constipation and abdominal pain,etc,and relative diseases include food protein-induced enteropathy,food protein-induced enterocolitis syndrome,food protein-induced enterocolitis syndrome,food protein-induced proctocolitis,celiac disease,eosinophilic gastroenteritis,eosinophilic esophagitis and infantile colic,etc.Delayed diagnosis will result in failure to thrive,anemia and hypoproteinenia.Therefore,early diagnosis and treatment can effectively prevent malnutrition and improve the children's animation.

Helicobacter pylori infection in children can cause a variety of gastrointestinal and extra-digestive diseases, even the gastric cancer.Most Helicobacter pylori infections are acquired in childhood and can cause various manifestations such as nausea, vomiting, anorexia, idiopathic thrombocytopenic purpura, refractory iron deficiency anemia, and growth retardation.In recent years, many advances have been made in the study of children′s Helicobacter pylori infection.This review focuses on the risk factors of Helicobacter pylori infection in children, containing the perspectives of Helicobacter pylori strains, hosts and environment, and looks forward to further research directions.

Objective To find out the clinical characteristics related to neonate food allergy.Methods Ten subjects were diagnosed as neonate food allergy at the Third Hospital of Peking University from January 201 3 to January 201 5.The following clinical data:the gestational age,genter,age of onset,feeding,clinical manifestations,white blood cell count,eosinophilic granulocyte count,C -reactive protein(CRP),routine stool test and occult blood test,blood spe-cific IgE of cow′s milk and clinical outcomes were investigated.Results There were 4 term infants,and 6 preterm in-fants,including 2 very -preterm subjects.The gender ratio between male and female cases was 73.The age of onset from 1 day after birth to 43 days after birth,clinical investigation of neonate food allergy in 1 0 cases,and the average time was 20.3 d,the median age was 1 8.5 d,and the SD was 1 3.38 d.Their rectified gestational ages were from 30 to 37 weeks in 6 cases at onset.Four infants received breast feeding,3 infants received formula milk feeding,and the other 3 infants received mixed feeding.At onset,the symptoms were almost involved in the digestive system.The white blood cell counts of lab test were almost normal in 1 0 subjects.And eosinophilic granulocytes were elevated in 8 subjects.CRP elevated in 1 case,and those of the other 9 subjects were normal.The cow′s milk specific IgE antibody was elevated in 1 subject,and that of the other 9 subjects was normal.Two subjects were performed opened food challenge test and the finding were positive.Conclusions Both the term infants and the preterm infants can have food allergy,but the age of onset ranged widely.Breast feeding infants can also be attacked.The symptoms of the digestive tract were the main clinical manifestations of such neonates.The open -food challenge test is beneficial to diagnose but difficult to practice in the neonates.Dietetic treatment is the only method can therapy the disease.And mostly the clinical outcomes are desirable.

0.05). Conclusion LCP enrichment formula is suitable to premature infants. Its lipid composition is more close to that of breast milk and benefit to the brain and retina development of premature infants.

Objective To study the serum and gastric juice levels of epidermal growth factor (EGF) in response to early minimal enteral nutrition (MEN) in premature infants with severe illness and evaluate the clinical significance of early MEN. Methods Premature infants with critical score

Objective To study the risk factors,clinical manifestations,drug sensitivity and outcomes of preterm infants with aerogenes infection in NICU.Method Preterm infants diagnosed to have infection of aerogenes in our NICU during July 2014 to October 2014 were selected as the infection group in our study.Uninfected preterm infants whose gestational age and birth weight were similar to the infants in infection group were selected as the control group.The ratio of number of infants in infection group and control group was 1 ∶ 2.The basic situation,clinical application of antibiotics before infection,defecation times,invasive manipulations,and parenteral nutrition time of the two groups were retrospectively collected.The clinical manifestations,drug sensitivity and outcomes of preterm infants with aerogenes infection were analyzed.Result There were 8 infants in infection group (male:female =3∶5).The birth weight ranged from 780 to 2 760 g;and gestational age from 28 to 33 w.There were 16 infants in the control group (male:female =1 ∶ 1).The birth weight ranged from 1 070 to 1 780 g,and gestational age,from 29 to 33 w.The incidence of prenatal infection in infection group was higher than that in the control group (3/8 vs.4/16,P ＜ 0.05).Comparing the two study groups,there were statistical differences between them in the following aspects (all P ＜ 0.05):non-invasive respiratory support time [11 (6,36) d vs.4 (0,6) d] and invasive mechanical ventilation time [(1 (0,6) d vs.0 (0,0) d].All the 8 infants in infection group had pneumonia,3 of them with sepsis (1 case was extremely low birth weight infant,and 2 cases were very low birth weight infants),and one of them died from septic shock.Drug sensitivity analysis showed that aerogenes were resistant to all the third generation cephalosporins,and were sensitive to Meropenem and Piperacillin/Tazobactam.The resistance rates of Imipenem were 1/6 in the first month,2/6 in the second month,9/11 in the third month,and 2/4 in the fourth month,respectively.Conclusion Avoidance of prenatal infection and shortening of the application of ventilator may reduce the incidence of aerogenes infection.Most of infants with aerogenes infection have favourable prognosis.The resistance rate of third generation cephalosporins is very high.Aerogenes could develop resistance quickly to the antibiotics which is sensitive initially.

Objective To investigate the epidemiological and clinical characteristics, risk factors, outcome and prevention strategy of very low birth weight infant (VLBWI) with nosocomial infection in neonatal intensive care unit (NICU). Methods The VLBWIs whose birth weight were less than 1500 g and hospital stays were more than 48 hours in NICU of Peking University Third Hospital from January 1, 1998 to December 31, 2008 were selected in this study. They were divided into nosocomial infection group and non-infection group. The clinical features and outcomes of nosocomial infection were summarized and the risk factors of which were analyzed with Logistic regression. Results There were 158 VLBWIs who fit for the criteria of our study during the eleven years, the mean birth weight was (1263.8± 155.5) g and the mean gestational age was (30.4±2.1) weeks. There were 70 times and 56 cases suffered from nosocomial infections. The incidence of nosocomial infection was 35.4% and hospital stay-related incidence was 14.4‰. Among 70 times of infections, there were 40(57.1%) pneumonia, 22(31.4%) septicemia, 4(5.8%) thrush, 1(1.4%)conjunctivitis, 1 ( 1.4%) upper respiratory tract infection and 2 (2.9%) unknown site infections.Forty-one strains of bacteria were isolated from 121 specimens, among which gram-negative bacillus accounted for 56.1% and gram-positive cocci for 46.3%. The duration of hospital stay of VLBWIs with nosocomial infection was significantly longer than that without [(43.7±15.5) d vs (26.3±14.4) d] (t = -7.058, P＜0.01). The fatality rate of VLBWIs with and without nosocomial infection was 3.6% (2/56) and 3.9% (4/102), and there was no significant difference (x2 = 0.012,P＞0.05). Logistic regression showed that mechanical ventilation (OR = 3.388, 95% CI: 1.656-6.932, P=0.001) and parenteral nutrition (OR= 7.054, 95%CI: 2.005-24.813, P=0.002) were risk factors of nosocomial infection. Conclusions The incidence of nosocomial infection in VLBWIs in NICU is high. Mechanical ventilation and parenteral nutrition should be avoided and the duration of invasive operation and treatment should be shortened as much as possible to minimize the chances of nosocomial infection in VLBWIs.

Objective: To investigate the impact of early antibiotics treatment on intestinal microbiota in preterm infants. Methods: The cohort study was performed from January 2015 to June 2015 in Neonatal Intensive Care Unit of Peking University Third Hospital. A total of 33 preterm infants were enrolled, among whom 25 were antibiotics-exposure group, and 8 were non-exposure group. Serial stool samples were collected on the first day, 14th and 30th days of life and analyzed by high-throughput sequencing. In exposure group, intestinal microbiota was also analyzed at 8 months to 1 year of age. Categorical variables were analyzed with χ² test, and continuous variables were analyzed with t test or non-parametric test. Results: Proteobacteria was the most prominent flora after birth in all cases (exposure group 69.6%, non-exposure group 83.7%) . In exposure group, at the phylum level, Proteobacteria was the dominant bacteria within the first 30 days, followed by Firmicutes after 30 days of life. At the genus level, Escherichia was the most abundant genera within 30 days after birth, while Veillonella became dominant after 8 months to 1 year of life. In non-exposure group, at the phylum level, Proteobacteria was the dominant phylum within the first 30 days. At the genus level, Actinobacteria (37.5%) was the dominant genus after birth, followed by Escherichia within the first month. Intestinal bacterial abundance and diversity were lower in exposure group, which was most significant on 30th day of life (shannon index 2.6 vs.3.4, ACE index 563.9 vs.591.6) . The influence of single antibiotics was less significant than combined treatment (shannon index 2.7 vs.2.5, ACE index 727.3 vs.492.9) . At the genus level, compared to non-exposure group, there were significant decrease of Escherichia (9.3% vs. 54.3%, Z=-2.830, P=0.005), Klebsiella (0.03% vs.12.4%,Z=-2.240, P=0.025), and Clostridium (0.2% vs. 4.8%, Z=-2.979, P=0.003) in exposure group on 14 days of life. Bifidobacterium (0.1% vs.2.0%, Z=-2.349, P=0.019) in cases treated with combined antibiotics was lower than that treated with antibiotic monotherapy on 30 days of life. Conclusions Early application of combined antibiotics impacts on the intestinal microbiome of preterm infants significantly. The infants who have received antibiotic after birth have lower quantity and diversity of Clostridium, Lactobacillus, Bacteroides and Bifidobacterium.

Helicobacter pylori (Hp) plays an important role in the development of a variety of digestive diseases in children, but in addition to Hp, there are many other gastric microbiota also critical for children′s health.At present, the characteristics of children′s gastric microbiota may be still relatively unclear.This artical summarizes the composition, succession process and function of children′s gastric microbiota, and reviews the relationship between gastric microbiota and Helicobacter pylori infection in children.

Objective:To investigate the relationship between gene polymorphism of rs2228055 locus in the exon region of interleukin-10 receptor A (IL-10RA) and susceptibility to food allergy in children.Methods:This was a case-control study. The food allergy group had 150 children who were diagnosed with food allergy in the Pediatric Food Allergy Clinic of Peking University Third Hospital from August 1, 2017 to November 30, 2018. Another 150 healthy children attended Child Health and Development Center in the same hospital were selected as control group. The genotypes of rs2228055 locus in both groups were detected by PCR re-sequencing. And the genotypes and allele frequencies of rs2228055 locus were compared between these two groups, as well as between food allergy children with positive and negative allergen specific IgE, and between those with and without involvement of different organs. Using the computer virtual mutation to stimulate the changes of amino acid caused by change of rs2228055 locus allele, to analyze the effect of amino acid changes on the structure of IL-10RA. The chi-square test was used for comparison between groups.Results:(1) There were 92 males and 58 females in food allergy group, and 86 males and 64 females in control group, without any statistically significant difference (χ 2=0.497, P=0.481). The ages of the two groups were 4.2 (0.1-15.0) and 8.0 (0.1-14.0) years old, respectively, the difference was statistically significant ( Z=-6.109, P<0.01). (2) The genotype frequencies of rs2228055 locus in the food allergy group and the control group were as follows: AA accounted for 73 (48.7%) and 98 (65.3%), AG accounted for 62 (41.3%) and 42 (28.0%), and GG accounted for 15 (10.0%) and 10 (6.7%), respectively. The allele frequencies in the two groups were as follows: 208 (69.3%) and 238 (79.3%) for A, 92 (30.7%) and 62 (20.7%) for G, respectively. AG and GG genotype frequency and the allele G frequency in food allergy group were significantly higher than that in control group (χ 2=8.501 and 7.862, P=0.014 and 0.005, respectively). (3) There were no significant differences in genotype frequencies and allele frequencies of rs2228055 locus of allergen-specific IgE-positive and negative food allergy children (all P>0.05). (4) There were no significant differences in genotype frequencies and allele frequencies of rs2228055 locus in the manifestations of skin, digestive system and respiratory system in food allergy children (all P>0.05). (5) The computer virtual mutation showed that the mutation energy was -0.08 without any increase in the stability of IL-10RA when the amino acid encoded by rs2228055 locus was changed from isoleucine to valine. Conclusions:The frequencies of genotype AG, GG and allele G of rs2228055 locus in the IL-10RA exon region in food allergy children are higher than that in non-allergic children, and those with the G allele are more likely to develop food allergy.