Please select the eligibility criteria that correspond to the clinical trial below.
Title: Gut Microbiome Study in Preterm Infants - a Norwegian Multi Centre Study
Brief Summary: Necrotizing enterocolitis (NEC) is a leading cause of morbidity and mortality among infants in the neonatal intensive care unit (NICU). It has been postulated that abnormal colonization of the preterm gut, or an unfavorable balance between gut bacteria may contribute to the development of NEC.

Recent clinical randomized studies and meta-analysis have shown that proactive colonization of probiotic bacteria reduce the frequency of NEC. Based on this evidence, in April 2014 all Norwegian NICUs started routinely administration of probiotics to all extremely premature neonates susceptible to NEC (gestational age \<28 weeks/birth weight \<1000g).

The current project is investigating the gut microbiome in patients receiving probiotics and compare the the gut microbiome with moderate premature infants not receiving probiotics. In addition, we are including a control of healthy full-term infants.

Samples containing feces from participants will be analyzed by state of the art whole-genome sequencing techniques. Bacterial diversity will be analysed with bioinformatic tools.

Study hypotheses:

* Probiotics given to extremely preterm infants will change the biodiversity of the gut microflora.
* Antibiotics given to these patients may influence the gut microflora also in infants receiving probiotics. In particular use of vancomycin may change the gut flora.
* After cessation of probiotic prophylaxis the gut flora of infants receiving probiotics will gradually resemble the gut flora of infants not receiving probiotics.
* A cross-contamination of probiotic bacteria between patients treated with probiotics and patients not treated with antibiotics may occur.


Options:
A: Inclusion Criteria:

* Preterm infants with gestational age 24-27 weeks/birth weight \< 1000 g, treated with probiotics (target number 26)
* Preterm infants with gestational age 29-31 weeks/birth weight 1000-1500 g, not treated with probiotics (target number 26)
* Term infants (target number 10)

Exclusion Criteria:

* Extremely preterm infants with gestational age below 24 weeks
* Preterm infants (24-31 weeks) with life threatening complications during 1 week of age
* Infants with congenital malformations
B: Inclusion Criteria:

* Cyanotic congenital heart disease
* infants \>35 weeks of gestational age
* Born at or transferred to Sami Ulus CH

Exclusion Criteria:

* Congenital anomalies of the intestinal tract
C: Inclusion Criteria:

* Preterm infants ≦ 34 weeks gestational age and birth weight below 1500 gm and who survive to NICU are eligible for the trial.

Exclusion Criteria:

* severe asphyxia (stage III),
* fetal chromosomal anomalies,
* cyanotic congenital heart disease,
* congenital intestinal atresia, gastroschisis, omphalocele, active upper gastric intestinal bleeding,
* lacking/refused of parental consent,
* those who are fasted for \>3 weeks during the study period.
D: Inclusion Criteria:

* Very low birth weight infants \< 1500 gr

Exclusion Criteria:

* Genetic anomalies
* Not willing to participate
* Allergy to S. boulardii components

Answer: A