Background/Aims: A longitudinal prospective cohort study was designed to investigate genome instability biomarkers in the offspring of Australian mothers at low risk of pregnancy complications and to test whether they are influenced by the type of infant feeding.
Methods: Genome instability was measured by the Cytokinesis block micronucleus cytome (CBMN-Cyt) assay in peripheral blood lymphocytes collected from cord blood (n=92) and from infants at 3 (n=69) and 6 months (n=56). DNA damage biomarkers expressed ex vivo were measured per 1000 binucleated cells including micronuclei (MN), nucleoplasmic bridges (NPB), nuclear buds (NBUD), apoptotic and necrotic cells. Nuclear division index (NDI) was measured using the frequency of mono-, bi- and multinucleated cells. Each infant was assigned a feeding score (FS): exclusively breast fed: 4; partially breast fed: 3; exclusively formula fed or other milk (soy or cow): 2; partially formula fed or other milk: 1.
Results: None of the DNA damage biomarkers measured was correlated with average FS. The decline in MN, NPB and NBUD at 3 months (28%. 53%, 35% respectively) and at 6 months (23%, 58%, 36% respectively) relative to cord blood could not be attributed to the type of feeding.
Conclusions: To our knowledge, this is the first study to have collected genome instability biomarker data for South Australian infants using the CBMN-Cyt assay. 67% and 38 % of babies were exclusively breast fed in the cohort that may have influenced observed non association between FS and DNA damage biomarkers.
Funding Source: Cancer Council South Australia