The BLOOM-LTFU study has evolved into the ongoing BLOOM-PCS Study (REB20-1442).

This is a prospective, observational clinical cohort study involving children born very preterm at less than 31 weeks and six days gestation. The purpose of this study is to investigate the microbiome (the collection of microbes in a biological site) alternations resulting from preterm birth and associations with the risk of immune dysregulation, asthma and allergies.

One important factor in gut health is the large community of microbes (tiny living things such as bacteria) that live on the human body called the microbiome. Recent studies have shown that premature babies are more likely to have changes in their gut microbiome that are associated with health issues. However, the specific microbiome features that are involved in the development of premature babies is still unknown. Therefore, this study examines the impact of very premature birth on the baby's microbiome, and how microbiome alterations are involved in health issues such as immune dysregulation, allergies and asthma.

The large communities of microbes in the gut play a major role on the microbiome that will form during infancy and childhood. Factors such as diet, exposure to antibiotics, surgical procedures, and mode of delivery, can strongly affect the dynamics microbiome development. It is well known that microbiome alterations are associated with disorders such as asthma. However, the features involved in disease development and progression are highly understudied. Through this clinical study, we will evaluate associations between the early patterns of microbial colonization in premature infants and their risk to develop asthma later in childhood.

The hypothesis of the study is that microbial alterations resulting from preterm birth causally contribute to the allergy and asthma risk in infants (defined by atopic-wheeze) through immune mechanisms.

Inclusion Criteria:

1. Born at ≤ 31 weeks + 6 days gestation (316/7 weeks);
2. Previously participated in the PROBIO and/or BLOOM PTN and/or BLOOM PTB research studies.
3. Provide a signed and dated informed consent form.
4. Willing and able to attend a clinic visit at Alberta Children's Hospital in Calgary, Alberta.
5. Parent/guardian providing consent must be able to speak and understand English.

Exclusion Criteria:

1. Has congenital gastrointestinal anomalies or has a history of gastrointestinal surgery.
2. Has major chromosomal anomalies.

The study recruits very early preterm infants that previously participated on at least one of the PROBIO, BLOOM PTN or BLOOM PTB studies.