The Amsterdam Infant Microbiome Study

Rationale: Childhood overweight and obesity have become an epidemic problem
worldwide. Also in Amsterdam, 19% of the children are currently overweight or
obese. Another public health problem is dental caries. in The Netherlands,
nowadays 41% of the five-year-old children suffer from caries. Increasing
evidence points to the microbiome as potential explanatory these chronic
diseases. The human microbiome develops in the first three years of life and is
influenced by a range of environmental factors such as mode of birth, type of
feeding and antibiotics use. A disturbance of the microbiome may affect the
onset of weight gain and caries. However, studies in early childhood that
examine the full development of the microbiome in relation to weight gain and
caries are lacking.

Objective: We propose the Amsterdam Infant Microbiome Study (AIMS). The general
objective of AIMS is to establish a research infrastructure that allows for
explorative research on the development of the microbiome in relation to
healthy growth and development. There will be a special focus on growth
trajectories and oral health, and special attention for the role of nutrition
and other lifestyle factors in children aged 0 - 3 years old from the
ethnically diverse population of Amsterdam.

Study design: AIMS is a multi-ethnic, prospective birth cohort study in 1,000
children, their mothers and other family members (i.e. partner and one
sibling). Mothers will be recruited mid-pregnancy and the infants will be
followed from birth until the age of 3 years. We will collect bio samples from
the children at 11 time points from birth until the age of 3 years and from
their mothers at 3 time points (during pregnancy, birth, and when the infant is
6 months old). Also, we will collect bio samples from the partner and sibling
during pregnancy of the mother and when the infant is 6 months old. We will
collect faecal-, vaginal-, saliva-,tooth plaque,- skin-, and breast milk
samples from the mother, and faecal-, tooth plaque-, saliva- samples from the
infant, and partner/sibling. Hence we will focus mainly on the gut and oral
microbiota.

Nature and extent of the burden and risks associated with participation,
benefit and group relatedness:
The study described in this protocol will be an observational study. The data
will be collected by means of questionnaires, and anthropometry as part of the
regular youth health care. We will collect bio samples that are all
non-invasive. In addition, we will collect clinical data using the BodPod®
when children are three years old , and perform clinical oral examinations by
professionals in both mother and infant when the children are 14 and 36 months
old. We expect no adverse or serious adverse events of these non-invasive data
collection methods. Where possible we want to limit the participant burden as
much as possible by for example using self-collection kits. There is no group
relatedness attached to this study since all ethnicities will be included.

This study will allow us to really disentangle under which lifestyle,
nutritional and environmental factors the changes in the microbiome of the
infant occur, to study when they occur, and to study how these changes are
related with growth trajectories and oral heath in the different ethnic groups.
Results of this study may open up new avenues for the prevention of childhood
overweight and obesity and oral health problems.