Thesis defense Lotte van de Venis (Donders Series 656)

7 June 2024

Promotors: prof. dr. A.C.H. Geurts, dr. B.P.C. van de Warrenburg, prof. dr. V.G.M. Weerdesteyn

Co promotor: dr. J.H. Nonnekes

Mobility, Stability, Adaptability: The challenges of walking for people with Hereditary Spastic Paraplegia

This dissertation contains cross-sectional and longitudinal studies that examined associations between nutrition and behaviour. For behaviour, executive functions and inhibitory control were specifically examined. Early life is an important life phase where infant and child development can be influenced by many external factors. Specifically, early life nutrition was examined. The first aim of this dissertation was to investigate the relations between breastfeeding factors and toddler behaviour. The microbiota-gut-brain axis, or the communication route between the gut microbiota and the brain, is an important mechanism that could explain the expected associations. The second aim was therefore to investigate the relations between gut microbiota and behaviour in toddlers. As nutrition plays an important role in the development of the immune system, neurodevelopment, and more, it is important to investigate the determinants of dietary intake. One developmental stage in which healthy nutritional behaviours are at risk is adolescence. Because maternal caregiving behaviour predicts a range of child developmental outcomes, it is possible that it can predict adolescent nutritional as well as impulsive behaviours (inhibitory control). The third aim was to investigate the role of the maternal caregiving quality, between birth and adolescence, in adolescent nutritional behaviours and inhibitory control. This dissertation found evidence that specific sugars in breast milk and certain gut bacteria predict better executive functions in toddlers. A link has also been found between better inhibitory control and higher adolescent diet quality. Although these findings cannot prove causal relations, the results indicate that early life nutrition and gut microbiota may play a role in toddlers' executive functions and inhibitory control. In addition, the results suggest that there is an interplay between inhibitory control and nutritional intake during adolescence.