Almost all New Zealand children have taken antibiotic medications by the time they are five years of age, according to new research from the University of Auckland’s Centre for Longitudinal Research – He Ara Ki Mua. The study authors were concerned that prescribing such a lot of antibiotics for young children unnecessarily could have serious long term consequences, most importantly encouraging the spread of antibiotic resistant bacteria. Overall levels of antibiotic dispensing in New Zealand are higher than in the United States and many European countries with the highest levels being for young children and the elderly. Antibiotic prescribing decisions for children in general practice often relate to doctors’ perceptions of parents’ expectations when seeking healthcare, as well as parents’ beliefs about antibiotics. Recent research has also shown that the first three years of life is a critical period for establishing a healthy microbiome – the healthy communities of bacteria that live in our gut, on our skin and elsewhere. It has been suggested that consumption of antibiotics at a young age may interfere with the developing microbiome and lead to permanent changes in immunity or metabolism. There is increasing evidence linking antibiotic use in young children to later weight gain and the development of chronic diseases, with asthma being one example.