Grant: Canadian Microbiome Initiative - LOI

Initial microbial colonization of the intestine during infancy has a crucial role in the development of the immune system, and environmental alteration in the composition of the normal microbiota may lead to the development of disease in children. Several studies, including our own, have linked antibiotic use in early infancy to the development of asthma and allergy in childhood. Disruption of the normal composition of intestinal microbiota, known as the microbiota hypothesis, is the proposed mechanism behind this association. By one year of age, two-thirds of Canadian infants will receive an antibiotic. While the microflora hypothesis is intriguing, much of the evidence is based on small studies of infants, using culture-based techniques that are unsuitable to detect many bacteria, particularly the anaerobes. Our SyMBIOTA research team proposes to study the effect of antibiotic use and diet on the composition of intestinal microbiota at age 3 months and one year, and the development of allergy and asthma in children. This will be a study of 1,500 infants enrolled in the Edmonton and Winnipeg sites of the Canadian Healthy Infant Longitudinal Development (CHILD) study. Study objectives will be achieved through linkage of detailed data on antibiotic use and diet in infants with clinical data and bacterial profiles of their fecal samples. The composition of microbiota will be determined using DNA sequencing techniques that will identify bacterial species on the basis of a PCR-amplified segment of the ribosomal gene. We have assembled an expert team of researchers and will be using the CHILD study infrastructure to enroll women during pregnancy and their newborns. The proposed methods are novel and are being tested at the Winnipeg site of CHILD. They will also be used to train the next generation of researchers. Knowledge gained from the SyMBIOTA team will inform guidelines for the judicious use of antibiotics during infancy.