Background: There are critical periods during pregnancy and early life when child’s neurodevelopment can be altered, where different factors including hormones, stress, genetics, and diet have an important role. Novel studies are indicating that also gut microbiota and maternal obesity can influence child’s neurodevelopment. Scope and approach: This review summarises the current concepts related to microbiota-gut-brain axis, including microbiota modulation of the eating behaviour, child’s cognitive function and brain structure, microbiota analysis techniques and neurodevelopment assessment in children. Further, we propose and present knowledge about potential mechanisms of action and ways to intervene for disease prevention and treatments, opening up an exciting area with important medical and industrial applications. Key findings and conclusions: This novel and fast developing research area is indicating that gut micro biota in association with body weight might have an important impact on foetal and child neurodevelopment. However, the exact mechanisms are not known and further research in the field is warranted. Within the MyNewGut Project we aim to analyse the impact of microbiota in association with body weight on cognitive and behaviour development in children. We will study the phylogeny and function of the gut microbial communities in overweight, obese and gestational diabetes pregnancies and in their progeny, in association with infants and children’s cognitive and behavioural outcomes. As well, the impact of gut microbiome on brain structure and function during childhood will be evaluated. Results from this study will shed light on the impact of maternal and offspring gut microbiome and body weight on child’s neurodevelopment, brain structure and function, and will suggest potential mechanisms for intervention. (C) 2016 Elsevier Ltd. All rights reserved.