Breastfeeding and child neurodevelopment – a role for gut microbiota? Invited commentary by Natalie Parletta Citation: Parletta N (2014). Invited commentary. Breastfeeding and child neurodevelopment: a role for gut microbiota? Developmental Medicine & Child Neurology, 56(2):101-102 The cohort study published in this issue by Julvez et al. 1 extends the body of research that shows a link between breastfeeding and neurodevelopment. Although it is well established that breastfed children have better neurodevelopment, it has been contended that this could be due to confounding factors such as SES and maternal IQ, which are fairly easy to control for, and less easily controlled factors such as mother-child bonding. Randomised controlled trials in this area are not feasible or ethical. However one cleverly designed study randomised mothers to a breastfeeding promotion condition and showed superior neurodevelopmental outcomes with the higher numbers of mothers in the promotion arm who breastfed their children 2 , although the latter study has been criticized for unblinded assessments of the children. This latest cohort study addressed the potential confounding of maternal bonding by measuring and controlling for maternal attachment and psychopathology, along with a comprehensive array of other variables including maternal education, IQ, SES status and environmental contaminants. The outcomes still showed a significant, independent link between exclusive, long-term breastfeeding and improved neurocognitive development in children at 4 years of age. The developing brain relies on a supply of essential macro- and micronutrients, and will not develop optimally (or at all) without them. It is becoming increasingly accepted that absence of nutritional deficiency and observable outcomes (e.g. cretinism as a result of iodine deficiency) does not necessarily equate to optimal brain development. There is a continuum